Environmental pollution as a result of a vacuum deficit in the working areas during asbestos removal work.

doi:10.21203/rs.3.rs-3787384/v1

The paper presents examples of the consequences of the lack of negative pressure in the work zone during asbestos removal. The results obtained for dust concentrations generated during these works in the work zone were relatively low compared to the literature data. This was due to the leakage of barriers restricting the work zone and the 'leakage' of dust. Therefore the asbestos content in the outdoor air in the vicinity of the renovated rooms was increasing. In the discussed cases, those works polluted the outdoor air for up to 15 m. The risk of asbestos dust content in the cleaned building outside the work area also increased. Those places often are not well controlled. Therefore, this may lead to long-term retention of asbestos dust in the facility despite the completion of the process of removing asbestos products from it. For example, non-friable asbestos- cement sheets removal in those work conditions increased contamination up to 3000 f/m³ outside the work zone. In the case of work with friable asbestos in building type “LIPSK”, contamination locally was up 21 000 f/m³. These values are above the average concentration of asbestos fibres in buildings of this type normally used and after works to correct asbestos removal (< 300–400 f/m³). Reported indoor air research results from the work zone in the case of the lack of negative pressure, without documented sampling conditions and contractor working methods, can falsely suggest a high standard of work quality.

Earth and environmental sciences/Ecology

Earth and environmental sciences/Environmental sciences

Health sciences/Diseases

Health sciences/Health care

Health sciences/Health occupations

Health sciences/Risk factors

Physical sciences/Engineering

Physical sciences/Materials science

Physical sciences/Nanoscience and technology

asbestos

building materials

indoor air

outdoor air

contamination

airborne asbestos fibre

asbestos removal

Asbestos removal with simplified asbestos removal methods and the absence of a vacuum in the working area make it difficult to assess the effectiveness of the work and pose unknown risks to bystanders.

1.1 Background

The literature on exposure to airborne asbestos fibres regarding asbestos removal usually provides us with information on known and correct works. Rarely the opposite. This article tries to change that. Many works carried out inside the building have common errors: too large and insufficiently hermetic, separated work zones, and too low or no vacuum in the working area. Asbestos removal work outside a building is sometimes considered to require less stringent equipment and dust control requirements than work carried out inside a building. This occurs mainly in large and unusual buildings. Workers can obtain an effect of the transfer and dispersal of asbestos dust from unsealed work zones outside, but first and foremost this is due to the need and opportunity to reduce the cost of the work. When external or internal work zones are not air-tight, the concentration of fibre in the workplace and the worker’s breathing zone are lowered in both circumstances. At the same time, the concentration in the surroundings increases. It's a natural result of dust transport in the air. It depends on the weather conditions, the scale and time of the works, and their duration. In many countries, there are no limits for such leakage from the work zone or limits for post-work contamination. There is no limit value for the concentration of fibres in the indoor air during the use of buildings containing asbestos materials. This makes it difficult to assess the effects of such faulty work. Final air tests, commonly used in assessing the quality of ACM (asbestos-containing products) disassembly cannot always reveal execution errors of works. Despite the passage of time, elevated levels of asbestos fibres may appear with a delay after the final cleaning work is completed and persist in indoor air after the removal of the ACM. As a result, many people who are not contractors and not protected by individual protection can be exposed to asbestos dust for some time. These exposure levels are generally not measured or assessed.

1.2 The problem study

During asbestos removal the risk of asbestos applies not only to contractors, but alsoto users of buildings during and after the construction work. Generally, living near the source of asbestos increases the risk of lung cancer [1]. It concerns not normal (passive) operation, but the states of product destruction and increased dustiness during renovation or asbestos removal. Exposure to air contaminated with asbestos fibres results in asbestos-dependent diseases of the respiratory system (lung cancer, mesothelioma) Asbestos mineral fibres have a virtually unlimited "lifetime" and travel distance (downwind) in the environment. Detection of asbestos in outdoor air, particularly with periodic emission of asbestos sources, can be unreliable. The contamination disperses rapidly in the environment. This is dependent on many external factors. Only large and constant dust emissions, such as the manufacturing process, give a relatively good answer to the relationship: distance from the source - concentration in air. Emissions associated with asbestos removal work or building demolition are periodic and lower than the production process. For economic reasons, this results in a willingness and ability to use economical work techniques of lower quality. This creates a risk of permanent or periodic (local) air pollution from asbestos dust, which can accumulate pollution over a larger area in renovated building. (See Appendix A, in Fig. A1) Threshold limit values TLV limits have been drastically lowered over time, as mesothelioma can develop even at very low doses of exposure [2]. An estimation of the long-term effects of asbestos exposure can be given with a large scatter of risk values [2]. According to an assessment of the health effects of past environmental exposure to asbestos, at an exposure level of 9 fibres/m³, a lifetime risk of mesothelioma of one case/per 100,000 people can be expected [3]. Others estimate such an effect at exposure of 1,000 f/m³ [4]. Consequences of environmental exposure may affect categories not included in the classical list of at-risk professions, where the problem of airborne dispersion of fibres from asbestos-containing materials remains, above all, during routine maintenance work or natural degradation [2]. Since the 1980s, the number of mesothelioma cases in ACM users outside industrial manufacturing sectors increased. That has drawn attention to the risks associated with relatively low cumulative exposures [5]. Non-occupational exposure to asbestos may explain approximately 20% of the mesotheliomas in industrialized countries [6] and the risks of mesothelioma from non-work-related exposure to asbestos are consistent with the response to fibre-type potency seen in the occupational setting [7].

Therefore, the question arises whether the action of general asbestos removal does not pose an increase in exposure to asbestos as an effect of wrong workmanship [8].

Of the historical measurements of occupational asbestos exposures in product production and construction work, 26% of results exceeded 3 f/ccm. About 29% were in the range of 0.6 - 3 f/ccm. About 44% of the results were in the range < 0.1 - 0.6 f/ccm. About 50% of the results of mean measurements of asbestos fibre concentration were in the range of 0.1 - 3 f/ccm in the min-max range from 0.04 to 7 f/ccm (9).

Presented examples of the work had no sufficient vacuum in work areas. (Air samples were taken by the author mostly inside and outside the work area, at a distance of more than 5 m from workers. The obtained values with "area samples" are not equivalent to the measurement values of samples taken from the worker's breathing zone (they are much lower [10, 11, 12]). The article presents the levels of pollution which are routinely not measured (outside the work zone). Determining the size and impact range of those specific mistakes was the aim of the work.

1.3 Literature data on exposure values

There are three types of measurements to consider. Individual and area inside work areas. The third one is the surrounding. To compare the variations in measured values between work areas and their surroundings, please refer to Appendix A, Tab. A1 – A3. Tese tables display the author's data recorded using the PCM + PLM technique during different asbestos-related tasks. The differences in exposure levels of people exposed in and out of the work zone at one of the “LIPSK” building types are shown in Fig. A1 in Appendix A. Result of measurements at various distances from the emission source are presented in Tab. A2. Differences in asbestos dust concentrations during operation and asbestos removal are presented in several examples in the literature data below in Table 1.

Table 1 Asbestos fibre concentration in indoor air (literature data)

The air measurement in buildings	Analysis Method	Asbestos concentration [f/m³]	[references]
Exploitation phase of a building
Schools, residential buildings, and offices	TEM	100–300 fibres 10,000 asbestos structures¹	[13]
Heating systems, using a soft insulation board, simulating operational disturbances	TEM	< 50	[14]
General	TEM	40 – 2,000, on average 200–500	[15]
Damaged ACM products in buildings	TEM	7,000–8,000 structures¹	[16]
Destruction process for asbestos removal
ACM roofing removal, area samples	PCM	600–16,000;	[10]
Demolition of houses with asbestos-cement products (roofs, facades), personal samples	PCM/ SEM	10,000 – 150,000 20,000–420,000	[17]
Estimated level of asbestos fibres exposure to workers during improperly performed disassembly works of ACM sprayed products	PCM	An extrapolation considering the duration of exposure: 100,000,000	[18]

¹TEM counted asbestos structures - fibres and fibre associations below the dimensions and geometries assumed for the respirable fibre [s/m³]

The value of the asbestos fibre concentration in personal samples can range from 50,000 – 20,000,000 f/m³ (2). The values of the asbestos airborne fibre during building use were determined in the wide range of 590 - 6000 f/m³ [19, 20,21] However, the values reported by researchers can vary significantly. They depend on the technique of analysis and sampling (see Table 1)

A simple conclusion showing the relationship between the scale of damage and the concentration of asbestos fibres in the air is not obvious in every situation [22, 23]. The concentration depends on many factors and does not always correspond to the visual observation of the scale of ACM damage, because some of them are immeasurable

(e.g. degree of intensity of use of the room - which translates into vibrations and air movement enabling re-emission of settled dust) or usually not recorded during sampling(e.g. building features).

The dust concentration changed depending on the formation and activity of new dust emission sources during the use of the building [22]. Significant differences were noted in the exposure of workers involved in the disassembly of roofing (from 0.3 to 0.6 f/ml) and façades made of asbestos-cement boards (below 0.1 f/ml) [11]. This can reflect the differences in ventilation between these buildings or erosion factors (insolation, differences in rain erosion). However, the author is inclined to believe that the weather conditions are similar, but the resistance to them is different. The facades are an autoclaved, pressed material, thanks to which they are more hardened than roof panels, although their chemical composition is the same. The result of an incorrect removal technique is presented in the studies of [18]. A wide range of levels of asbestos exposure have been described. In the case of dismantling works with asbestos-cement products, concentrations of 0.1 – 0.6 f/ml were recorded. In the case of improper removal of asbestos, even up to 100 f/ml were generated in the case of materials in form sprayed on construction. Such values affect the air quality outside the work zone and cannot be indifferent to the health of residents, even if they are periodic. Scientific reports show the dependence of exposure to cancer assuming exposure for 8 hours a day, 5 days a week for 40 years of working life [24]. A summary of the average levels of respirable (countable) concentrations of asbestos fibres in the air inside Polish buildings, during the use and removal of asbestos, taking into account changes over time, is described in articles [22, 25, 26] These data represented much lower values, measured in work zones or beyond them up to ≈ 50,000 f/m³. This resulted from the increased distance between the place of air sampling and the source of asbestos dust in the author's research. As per yearly averages, in buildings with friable asbestos, concentrations vary irregularly. It is usually, less than 1,000 f/m³, but in some cases, exposure reaches 10,000 f/m³ (fibres counted with an optical microscope) [2].

Workers in the finishing sector of construction are at risk of exposure to high concentrations of fibres. The air outside of their protective equipment has shown mean and median exposure levels of 0.4 f/ccm and 0.025 f/ccm, respectively. These levels have been found to range from less than 0.00001 to 200 f/cm³, as analyzed by TEM [24]. However, some databases could present much more scattered exposure values [9].

The basic inference from the literature data analysis showed that concentration values depend on the techniques and places of sampling as well as analytical methods used. The differences between these factors mean that only the results obtained with the use of similar research parameters and places should be compared. But even then, undiagnosed factors can cause discrepancies in numerical concentration values. An example of differences in the concentration of asbestos fibre value in outdoor air using a similar technique of measure, but in different places, can be a comparison of monitoring of central Poland and Mashhad City, Iran.

The first quoted data ranged in values from about 300 to 600 f/m³ [27]. The second one was measured with an average range of 11,400 - 14,400 f/m³ [28]. A comparison of such remote regions cannot ignore natural sources and the types of asbestos associated with them [29] (In Poland, they are practically non-existent and the air is dominated by chrysotile, a basic kind of asbestos in ACM products in buildings.)

The studies concerned the removal of friable and non-friable ACM inside and outside the buildings. Indoor and outdoor air samples were taken at the buildings that contained ACM, during the operation of buildings, asbestos removal, or building demolition. In all cases, there are significant, different technological errors in the removal of ACM. All described works were carried out by specialists in a careless manner and had in common the lack of a proper work zone. Mostly, these work zones were too large, or leaky, or had periodic vacuum failures (at night, when work was not carried out). They resembled the work of amateurs, not specialists. Some cases of work carried out inside and outside buildings were presented. A detailed demonstration of the working conditions for asbestos removal in the examples discussed is shown in the photographs in Appendix B: Figs B1; B2: B3 and B4.

Case 1. A large sports hall, external walls with ACM (asbestos-cement sheets).

The hall was a large sports facility (Fig.B1 in AppendixB). The walls were in the form of a disc, inclined from the vertical. It contained two types of asbestos-cement products: PW3 / A, sandwich panels with an area of 4,561 m² and a weight of approx. 51 tons and a façade, made of small tiles with an area of 3,457.6 m², weight approx. 98.5 tons. The curtain wall of the hall was made of PW3/A sandwich panels. This board consisted of a thermal insulation core made of polystyrene 4 cm thick, clad on both sides with an asbestos-cement board 6 mm thick. The PW3/A boards were separated from the stands by a technical space. There were two types of ACM: curtain wall and facade panels. In the construction of the curtain wall, the PW3/A sandwich panels were screwed to the steel structure. It was possible to unscrew in a non-destructive way PW3/A boards from the technical rooms under the stands. The façade panels were attached to wooden battens, attached to the surface of the PW3/A panels. A section of the facade of this building is seen in the lower part of photo 4a. During the disassembly of construction products, "friable" products remained in the building (threads and seals of the ventilation system that will not be removed.

Due to non-standard construction, the disassembly work was complicated. It was carried out without separation and encapsulation of the disassembly zones. In the work area, full containment and negative pressure were not performed. The PW3/A boards were removed by "digging" them out of the mounting strips. Tests were conducted inside the building, in external zones, on scaffolding, and up to 80 m from the building.

Case 2. Disassembly of the facade of a high-rise building without vacuum in the area - work zone

Due to the narrow construction and renovation scaffolding, it was not possible to disassemble the a-c boards (asbestos cement facade panels) as a whole, but only after they were broken into smaller fragments. (The situation is shown in Fig. B2. in Appendix B). The surface area of the asbestos cement panels (facade) was approximately 7,000 m². All façade panels, due to their size, were broken during removal from the building wall. The contractors of the works did not use a hermetic cover made of PVC foil to separate the work zone, but only typical construction mesh to protect thicker fragments of boards that could fall outside the work zone. Measurements of air contamination were taken on the scaffolding and inside the building.

Case 3. Dismantling of asbestos-cement pipes inside a large facility, without building an airtight work zone

Asbestos-cement pipes were being dismantled inside a drinking water treatment plant in a large city. Sequences of connected pipe sections containing ~23% of chrysotile and crocidolite asbestos were removed after cutting them down to size. (It was impossible to remove them as intact pipes). Errors: no air-tight sealing. The pipes were cut into 1.5 m sections and cutting involved chopping 2/3 of the pipe diameter with an axe (Fig. B3 in Appendix B). The remainder was broken with a hydraulic jack.

Case 4a Inadequate asbestos removal from walls and structures of a five-story "LIPSK" type building.

The structure of the building has been described in detail in previous articles [26, 27]. The building contained 140 t of friable and non-friable products in walls and steel structure. During work (Fig. B4 in Appendix B), between shifts, there was a loss of negative pressure in work zones due to "power outages". This was beyond the knowledge of the contractor and resulted in non-hermetic work zones.

During the dismantling of ACM, after each working day, when the closed building became empty (at night), the building security switched off the electricity to save energy. This shut down the vacuum-filtration units in the work areas, which should have been working continuously until the works were completed. The electricity was switched back on before work started. The workers were not aware of the repeated power cuts and vacuum drops. Asbestos dust contaminated the entire building. The tests were performed inside the building to monitor the dismantling and to control the so-called "leakage" of contaminants outside the work zone.

Case 4b A building with one floor out of use, where interior asbestos walls were damaged. Asbestos dust transmission from damaged "SOKALIT" boards on the 1st floor to the 5th floor which was normally used

Several sandwich panels named "SOKALIT" on the first floor of the building type “LIPSK” were significantly damaged. After determining the presence of asbestos in the damaged boards, all floors with rooms were closed and excluded from use. The analogue boards on the fifth floor were well-protected and had no damage. After a year, measurements of asbestos dust concentration were carried out on the first floor and on the fifth floor, which was normally used.

Case 5 Rapid demolition of a small 1-storey building without the use of separate working zones with negative pressure

For comparison, the monitoring of pollution during the demolition of a small, single-storey building type MOA. It contained friable ACM (approx. 40 t of ACM) in the external and internal walls and ceilings. The building was quickly demolished without prior asbestos removal. An analysis of changes in internal and external pollution during the demolition of this building was carried out.

3.1 Sampling

The studies of the effects of the works described here concern works carried out between 2000 - 2019. The air samples were taken mostly inside and outside the work area and the others (background) were some distance from the studied buildings. Two techniques of air sampling were used:

- static, (natural, stagnant conditions, where the ambient air was not additionally mixed); That was for the samples when the ACM products were disassembled;

- dynamic, only in rooms, where asbestos was not being currently dismantled. For example, it was done after or before asbestos removal. The air was mixed using fans to activate settled asbestos dust.

3.2 Sample analysis

Sample analyses were carried out using the PCM + PLM method (phase-contrast and polarized light microscopy), which has been previously, repeatedly verified by electron microscopy and comparative inter-laboratory studies. The samples were taken from inside the work zone, except the background samples, which were taken from a few meters away from the work in progress, or near the work zone (area samples). For this reason, the values of the area samples obtained here are not equivalent to the individual measurements of a sample from the breathing zone of workers. Their value is significantly lower. However, the information can provide a view of the scale of these threats. For microscopic analysis, the air samples were collected on filters made of Millipore AA cellulose esters with pore diameters of 0.8 µm. The flow volume of tested air of approx. 1.5 m³. The time of sampling through each filter was ensured for two hours. The samples from inside the work zone, except background samples, were taken from a few meters away from the work in progress, inside the work zone (area samples). Some of them, as a leakage, were sampled at a different distance from the work zone. Building preparation conditions: the windows in buildings were closed during air sampling.

Analysis details

The author personally sampled, analyzed the circumstances of the work and carried out air tests at various stages of the work in terms of the concentration of asbestos respirable fibres (countable fibres according to WHO criteria, L> 5 µm, Ø <3 µm and L: Ø < 3: 1). The sample analyzes were carried out using the PCM + PLM method (phase-contrast and polarized light microscopy), which has been previously, repeatedly verified by electron microscopy and comparative inter-laboratory studies. The applied analysis method was described previously [22, 30]. After chemically treating the filters, microscopic tests were performed, calculating the number of counted respirable fibres (PCM method), identified as asbestos fibres (PLM method). During microscopic analysis, the phase contrast technique according to the NIOSH 7400 method was used. The observation of each of the counted respirable fibres was supplemented with its identification using light polarization (based on optical features). The method of microscopic analysis using the OM technique was generally consistent with MDHS 39/41. The significant differences were the increase in the number of observation fields to about 400 and the use of magnifications up to 1000 x with immersion. The number of observations of a single filter was about 4 times higher than with the NIOSH standard, which increased the sensitivity of the analyses. The adopted limit of quantification for this method is 300 f/m³. The described method was a PCA-accredited research procedure developed in detail by the author and used at the Building Research Institute [31]. The expanded uncertainty of the results, determined in the computer program developed for the laboratory for these tests, amounts to approximately 20%. The selected microscopic research technique allows for a comparison of the historical results obtained by the author and other researchers, serving the assessment of threats. However, it does not pretend to be precisely marked as with the TEM technique [32, 33] Although the TEM technique (US EPA 2021) is recommended for the identification of fibres in outdoor air. The author, as a mineralogist, decided to use the method of optical microscopy. This was due to the need to compare current results to the earlier, obtained with the same method, and also with the literature conclusion [32].

Case 1

The impacts of demolition on the external environment during the 100 days of asbestos removal are shown in Tables 2 a and 2b.

Table 2a Changes of indoor pollution over time, during asbestos removal in a single daily test.

Indoor air		Before removal	Facade removal Start End			Removal of walls containing PW3/A
Days of work		0	1	15	29	34	36	42	54	59	72	96	110	f/m³
Place sampling	1	580 - 750	2,100	3,300	400	1,100	2,200	2,400	1,000	2,400	580	860	380
	2-3	< 300	1,000	7,100	300	1,100	700	1,300	900	1,000	1,200	460	390
	4	1.000	180–4,300	300 –3,000	300–600	1,000–1,200	1,350	1,500–1,600	Measurements have not been taken

Legend to Tab. 2a:

Place sampling of indoor air
1	Balcony (above the stands, against the wall)
2	The middle of the sports hall
3	Tribunes
4	Technical space next to the wall
	Period of the work
	Period out-of-working hours

Table 2b Changes in outdoor pollution. The concentration of asbestos about the distance from the object, during 110 days of monitoring in a single daily test

		Before work		Facade removal		Removal of internal PW3/A panels
Days of work		0		1 -15	29	34	36	42	54	59	72	96	110
Distance from source Outside the building [m]	80	f/m³	<300	900	800	300	400	500	700	<300	400	300	-
Distance from source Outside the building [m]	15	f/m³	<300	700–1,000	1,000– 2,000	Measurements have not been taken

Case 2

During the removal of elevation, indoor contamination inside the rooms with closed windows was averaged from 21 measurements < 300 f/m³, range 140–300 f/m³ σ = 100 f/m³;

Outdoor (measurements taken on the scaffolding platforms, ~2.5–5 m from the demolition of asbestos plates) 800–3,000 f/m³; σ = 700 f/m³; Measurements with individual, personal dust meters were in the range 20,000–70,000 f/m³. The effect of not covering the works is to contaminate the ground (Fig. 3)

Table 3 Asbestos contamination of the ground 20 m around the building (where asbestos has been dismantled).

No. samples	1	2	3	4	5	6	7	8	9	10	11	averaged	σ
A [%]	0.02	0	0	0.01	0.03	0	0.02	0	0	0	0	0.01	0,01
B [%]	0.02	0.41	0.03	0.26	0.14	0.54	0.02	0.04	0.20	0.11	0.04	0.17	0.17

The values of asbestos concentration in soil are given in percentage by weight [%].

Asbestos fibres separated from the soil as pure fibres from airborne
Asbestos fibres separated from the same ground as crumbs removed from the building of facade panels

Case 3

The distance of air sampling from pipe destruction was 4–15 m. Indoor contamination (inside the rooms) average 8,000 f/m³ range 6,000–20,000 f/m³; σ = 5,000 f/m³

Case 4a

Tables 4a and 4b show the numerical fibre concentrations in the 'clean zone' and the leakage as a result of work carried out in 'LIPSK' type buildings when the vacuum in the work zone disappeared or was insufficient.

Table 4a Migration of asbestos fibres in building contaminated by wrong removal ACM (periodic vacuum decay in the work area) Measurements outside the work zone, during works on the fifth floor¹.

Place of sampling		Registered leakage [f/m³] during three workdays in place adjacent to the work area, which was treated as a "clean" area.		Contamination of the building: "Leakage" - pollution outside the work zone, constituting [%] of the concentration inside the work zones
		Wrong renovated “LIPSK” (uncontrolled power outages)				An example of good standard works
		Range	Average /σ	After 3 days [%]	After 2 months [%]	After 3 days	After 2 months
V renovated floor		28,000 -51,000	39,000 / 16,000	not measured		7	0.1
Leakage	IV non-renovated floor	14,000 -23,500	18,700 /6,700	28	4-7
	III non-renovated floor	13,600–28,900	21,250 /10,800	27–60	9.2
	II non-renovated floor	3,200–7,700	5,500 / 3200	9.8–15.4	6.4
	non-renovated ground floor	1,800–5,700	2,500 / 2800	3.6–11.4	not measured

Table 4b Migration of asbestos fibres in buildings during too small during insufficient negative pressure in the work zone for the removal of friable asbestos materials in the LIPSK building in the work zone. Working vacuum 2 - 4 Pa instead of the required 20 Pa was caused by un-hermetic work zones.

Floor in building	Contamination in the building before asbestos removal work			Contamination in the building during asbestos removal work (outside the work zone)			Contamination in the building 7 days after asbestos removal work cleaning (in work zones)
	Average [f/m³]	Numb of sampling	σ [f/m³]	Average [f/m³]	Numb of sampling	σ [f/m³]	Average [f/m³]	Numb of sampling	σ [f/m³]
V	700	5	141	2,300	2	140	3,800	2	1,500
IV	260	8	200	2,700	2	1,000	12,170	2	15,300
III	260	6	220	4,700	2	2,100	13,000	1	not measured
II	160	4	100	4,000	2	2,000	not measured
I	300	2	140	not measured
staircase	300	2	150	21,000	2	10,900	not measured

Case 4b

Table 4c Dust migration in the building between floors from damaged ACM to clean rooms (lack of control over the flow of air and dust suspended in it).

Average asbestos fibre concentration on the I Flore with damaged ACM [f/m³]

Average asbestos fibre concentration on the V Flore with clean rooms [f/m³]

σ

[f/m³]

< 300

1,360

730

Tables 5a and 5b show the impact of demolished building-type MOA (with friable asbestos) on the surroundings over a short period.

Table 5a The demolished small building with asbestos and the neighbouring school building (in use, with closed windows).

Before asbestos removal						During and after asbestos removal
Measured places	No. of sample	Average [f/m³]	Max. [f/m³]	Min [f/m³]	σ [f/m³]	No. of sample	Average [f/m³]	Max. [f/m³]	Min [f/m³]	σ [f/m³]
Removal building	2	<300 (280)	312	<300	50	5	2,090	4,800	1,200	1,990
Outdoor air	< 300					5	1,020	2,240	<300	730
Adjacent school building (30 m)	2	< 300 (270)	< 300 (275)	<300	10	3	< 300 (290)	440	<300	170

Table 5b Changes in environmental pollution as demolition work progresses

Days of work	1	2	3	4	7	13	14	15	16	18	19	Place of measurement
Advancement of dismantling works	Before disassembly + preparation zones of work				Start	Walls	Roof	Final	waste disposal			Place of measurement
Fibre concentrations [f/m³]	<300	<300	<300	<300	<300	400	600	2,200	600	300	<300	15 m from the works, 2 m outside the building
	300	300	300	300	1,200	3,600	4,800	1,200	600	700	600	Inside the demolished building MOA
	<300	<300	<300	<300	<300	<300	<300	<300	<300	<300	<300	Inside the other building, 30 m away from the works

Table 5 b shows the changes in fibre concentration as the building demolition work progresses:

The disassembly of the roof caused the unsealing of the building and the mixing of pollutants inside with external pollutants. On the 19th day, the measurement “inside the demolished building" was carried out on the foundations, the remains of the demolished building, i.e. in the atmospheric air not limited by walls. For comparison, Tables A1 and A3 in Appendix A show some typical examples of asbestos fibre concentrations mixed at different distances from the emission source, during different improper asbestos activities, and disturbance of asbestos products. ACM destruction activities and measurements were carried out in an open space without dust barriers [22, 30].

The common recurring error of discussed work is the problem of correct preparation of the work zone, its air-tightness or its complete absence. As a result, there is no sufficient negative pressure in the work zone and the result is the penetration of asbestos fibres into the zones of the building where no work is carried out. All cases in the described rooms were characterized by a large spread of fibre concentration of the results. At the level of the air surrounding the building at a distance of about 10 - 15 m, the increase in pollution from the leak (cases 1 and 5) was delayed by at least one day, and the maximum values of fibre concentration reached 2,000 – 2,200 f / m³ (Table 2b and 5b).

A mistake made (sometimes deliberately) by contractors was the non-hermetic separation of the work zone. These were unsealed, with too small vacuum or without vacuum at all, or too large volume of zones, or not enclosed at all. The too-small vacuum caused the dispersion of asbestos fibre into the surrounding air and the migration of pollution throughout the building (case 4). Heavy ventilation of the building just before the air testing date can make it difficult or impossible to detect this trick during final control. In Case 5 the building was unsealed by removing the roof, walls and windows before asbestos removal was fully completed. This saved time and resources to control the dust released during asbestos removal.

Table 6 summarizes the cases regarding German regulations. The low concentration of asbestos fibres in the work zone was caused by the permanent exchange of internal and external air, and by the large cubature of the building (case 1). In terms of the type and scale of destruction of products that can release asbestos fibres into the air, the most similar cases are 4a and 5.

Despite the complete lack of appropriate technique, in case 5, the asbestos dust concentration limits for workers are not exceeded due to the unsealing of the building by removing windows and the roof.

Table 6 Summary of the chosen results, regarding German regulation TRGS 519²

Case	5	1	2 and 3	4a
The size of the building	Small, two-story	Wary big sports hall	Wary big buildings	Medium size, 5-story building
Type of work	Demolition	Asbestos removal	Asbestos removal	Asbestos removal
Type of ACM	Friable	Non-friable	Non- friable	Non- friable + friable
Conditions for air sampling (time from the completion of the works)	2 - 3 week	2 week	Measurements were not taken inside the buildings after the completion of the work	1 week
Average [F/m³]	1,200	≈ 400		3,800 – 13,000 (on different stairs)
Reason	No dust control when removing ACM, a lack of appropriate technique of disassembly, no separate work zone, no windows and no roof, and mixing of polluted indoor air with atmospheric air.	No separate work zone, mixing of polluted indoor air with atmospheric air		The work zone is leaky, negative pressure 5 times in the work zone is too high, and periodically (at night) completely turned off with negative pressure before the works are completed and the work zone is cleaned.
The effect², the limit exceeding	2,3 x limit	The limit was not exceeded, however, most of the asbestos dust from this work was discharged into the building's surroundings		7.6 – 26 x limit

The trend line of changes in pollution in outdoor air in the vicinity of large buildings with ACM removal as a function of distance from the dust source is graphically presented below in Fig. 1a and 1b. Pollution in “LIPSK”-type buildings with execution errors causing leakage from the work area is presented in Fig.2

Analysis of changes in air pollution in the cases in question

Case 1

Outdoor air pollution, generated during the disassembly of the ACM at a distance of 15–80 m from the pollution source, had values about 3–7 times lower than indoor air (Fig. 3a).

The maximum initial asbestos fibre concentration in outdoor air after removing the façade preceded the maximum concentration recorded inside the building. About eighteen days after the situation was reversed. This was caused by the unsealing of the walls of the building (as in Case No. 5). Outdoor air pollution and the dynamics of its changes were inversely proportional to the distance from the building. The charts depicted in Fig. 3a and 3b provide a clear representation of the diverse functions explaining the changes in dust levels detected at different distances from the structure.

Unlike the outdoor air, the indoor air was subject to large fluctuations during the asbestos removal. Although there was an inadequate separation between work zones and the rooms were quite large, the indoor air was characterized by significantly higher levels of changes and asbestos fibre concentration values. This was due to the higher concentration of dust generated at the emission source and the lower degree of dispersion of the airborne asbestos fibre. The values recorded using an optical microscope are on average half lower than those recorded using an electron microscope [33]. Literature data [11] provide in equivalent situations personal value exposure of 100,000 – 300,000 f/m³. However, the maximum “area value” contamination measured here, with similar works was only ≈7,000 f/m³. This means that the giant pollutant stream was dispersed in the external environment of the building. The residual volume outside at a distance of 15 m from the source was only ≈ 2,000 f/m³.

In Case 1, the graph of indoor air pollution changes is a polynomial function and is presented in Fig. 3b. It estimates the average concentration and contamination trend changes in this building during periods of renovation. Coloured points indicate the location of indoor samples at different distances from the dismantling walls [m].

Case 5

Fig. 4 presents trends of changes in air contamination during improper demolition of small building-type MOAs. The works caused a short-term increase in asbestos concentration in the outdoor air. At the maximum intensity of works (14th day of works), at a distance of 15 m from the works zone, there was a ≈ 7 - 8 fold increase in the concentration of asbestos in the air compared to the levels before disassembly. It took 4 days since the outside air returned to its original state before the asbestos removal work. Generally, the concentration of asbestos in the air inside the demolished building has impacted outdoor air pollution. Despite being located 30 meters away from the site, there were no significant variations in asbestos dust levels detected inside the school building. After analyzing Figures 3a, 3b and 4, it is evident that the concentration of asbestos in the air decreases significantly with an increase in distance from the emission source. The data also indicate a decreased dynamic of those variations in the levels of asbestos over time. Due to different physical processes, such as gravitational settling and air exchange in the building, asbestos fibre concentrations in all rooms and their surroundings decreased over time and varied depending on the prevailing conditions. The concentration of fibre and the shape of the curve changes of trend depended on: the scale and type of damage to the ACM panels, the time which had elapsed since the destruction of products, and the extent to which they were covered with paint. In the case of indoors, those changes at first depend on the ventilation of the rooms, the intensity of use, including vibration of the walls and floors, and the degree of air exchange. Although the values presented by the author in the general scope of building operation coincide with other reports [35] they are limited by the sensitivity of the technique used. From the presented relationships between various OM, SEM, and TEM methods, [33] it follows that the real exposure levels of workers, staff and building users, measured by electron microscopy would be 2 times higher than those measured by OM technique (which can register fibres with diameters > 0.2 µm). As a general conclusion, in described building situations, the risk of contamination of the building and its surroundings appears, but it can be hard to discover.

Air pollution values can be underestimated in and out of work zones due to leakage and mixing of indoor and outdoor air. The course of the indoor air pollution changes and trend line showing changes in the concentration of particulate matter over time (fig. 2, 3b and 4) are different in each of the discussed cases. This applies to the dynamics of change and the type of function that best approximates the trend line. The reason is the variety of conditions for the formation and maintenance of asbestos airborne fibre.

Taking into account the repeated exposure of workers, as well as the effects of improper work with asbestos in the neighbourhood, an increase in the risk of certain diseases as a result of asbestos exposure cannot be ruled out. Many sources are responsible for them, such as building environmental pollution and various factors other than the amount of momentary measured exposure [ 36, 37, 38, 39].

The results of air pollution "area measurements" aimed at evaluating changes in outdoor and indoor air during asbestos removal are dependent on many factors and sampling conditions. As a rule, they are not able to reproduce the actual existing levels, lowering them as compared to the values of the emission sources present.

The lack of sufficient negative pressure in the working area results in contaminants being dispersed throughout the building. It lowers the concentrations in the work area, transferring the contamination and hazard to other areas of the building and outside the building. This makes it impossible to reliably assess the effectiveness of the work

In case 1, the excessive volume of the work area falsified and lowered the exposure of workers more than 60 times. For this reason, the "low concentration" values obtained from such "surface" measurements were unreliable for assessing the quality of work.

In the outside air, the effects of failing asbestos removal disappear fairly quickly when the work is stopped after a few hours or days (depending on the activity of the source of the contamination). \

The concentration of asbestos fibres in the interior space of a building decreases with time. The course of the trend depends to a large extent on the air exchange in the building.

Concentrations measured on the facade or roof of such objects do not transfer from the sources at a distance of more than 10–15 m from them. However, people inside the building, regardless of the distance from the area of poorly performed work, may be exposed to the value of, inter alia, 0.2 OEL (0.2 x 0.1 f/ml).

Each disassembly of ACM-s temporarily causes a significant increase in asbestos dust pollution in the work zone and its vicinity. However, the asbestos removal process in a building does not affect the indoor air of adjacent buildings with closed windows, as the dust concentration drops sharply with increasing distance from the source.

When destroying ACM in a large room, the concentration of asbestos fibres varies greatly across its entire volume. The main reason is that the dust is dispersed over a large volume. For the assessment of such a state of contamination of such a volume, traditional sampling techniques are not representative, because the air that differs significantly in different parts of the room cannot be averaged (mixed) and the free access to the outside air lowers the dust value at the place of its formation.

The emerging EU legislation on the use of buildings with asbestos and on the risks involved in renovating them still does not adopt common limit values for indoor air contamination. The lack of adoption of such limits in many countries [40] has remained unresolved for years. This results in the exposure of occupants of operational and renovated buildings to unknown levels of concentrations of asbestos dust.

The policy of the EU countries on asbestos issues seems to be inconsistent. On the one hand, the project is under consideration for a DIRECTIVE OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL amending Directive 2009/148/EC on the protection of workers from the risks related to exposure to asbestos in the workplace 2022/0298(COD) allowing for a drastic reduction of the upper OEL value (reduction up of 10–50 x the current value). At the same time, the opinion of the EU Parliament (allows) the lack of appropriate asbestos-level indoor air regulation for exploiting buildings. Significant differences in the construction of 'insulated, airtight working areas' are allowed without defining the size of the negative pressure inside. In some countries, it is 40 − 8 Pa, in others no vacuum at all. Recognizing such regulations as an internal matter of member states seems the author is not correct (See Appendix A, in Fig. A1).

Statement of data available

All thematic data ( in tables: 2-5) generated or analysed during this study are included in this published article [ The supplementary raw data used in supplementary information files ( tables: A1, A2 and A3 in appendix A) are available from the corresponding author on reasonable request. ]

Conflict of interests

☐ The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

No financial / personal relationships which may be considered as potential competing interests

☐ The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: none

Author Contributions Statement (CRediT author statement)
The author declares that he is the sole author of the work. Therefore, he is also the corresponding author and responsible for all elements of the manuscript preparation.

The percentage of the author's contribution to the development of all elements of the manuscript (drawings, photographs, measurements, data analysis, preparation of the manuscript text) is 100% of the contribution.

Kyeongmin Kwak, et al., 2020. Environmental exposure to asbestos and the risk of lung cancer: a systematic review and meta-analysis. Occup. & Environ. Med., 79, (3). http://dx.doi.org/10.1136/oemed-2020-107222
Pira, E., et al., 2018. Asbestos exposure: past, present and future. J Thorac Dis., 10 (Suppl 2), 237–245. doi: 10.21037/jtd.2017.10.126
U.S. National Research Council of the National Academy of Science. Asbestiform fibres: Non-occupational health risks. Washington, DC: National Academy Press, 1984).
Mossman, B.T., 1991. Fibre carcinogenesis and environmental risks. In: Environment and Prevention, Ellis Horwood Ltd 1991, 241 – 55. [Google Scholar].
Iwatsubo, Y., et al., 1998. Pleural Mesothelioma: Dose-Response Relation at Low Levels of Asbestos Exposure in a French Population-based Case-Control Study. Am. J. Epidemiol., 148 (2),133 – 42. DOI: 10.1093/oxford journals.aje.a009616
Goldberg, M., Danièle, L., 2009.The health impact of nonoccupational exposure to asbestos: what do we know? Eur. J. Cancer Prev. 18(6),489–503 DOI:10.1097/CEJ.0b013e32832f9bee
Gary M. et al., Non-occupational exposure to asbestos and risk of pleural mesothelioma: review and meta-analysis Occup Environ Med 2017 74(11):838–846. DOI: 10.1136/oemed-2017-104383
Hajok, I., Marchwińska, E., Dziubanek, G., at al., 2014. Environmentally Related Diseases and the Possibility of Valuation of Their Social Costs", The Scientific World Journal. https://doi.org/10.1155/2014/284072
Database EV@lutil https://ssl2.isped.u-bordeaux2.fr/eva_003/
Lange, J.H., Thomulka, K., 2000. Air sampling during asbestos abatement of floor tile and mastic, Bull. Environ. Contam. Toxico. 64(4),497–501. DOI: 10.1007/s001280000031
Brown, S.K., 1987. Asbestos exposure during renovation and demolition of asbestos-cement-clad buildings. Am. Ind. Hyg. Assoc. J. 48(5):478–86. DOI:10.1080/15298668791385075
Dufresne, A., Dion, C., Frielaender, A., Audet, E., Perrault, G., 2009. Personal and static sample measurements of asbestos fibres during two abatement projects. Bull. Environ. Contam. Toxicol. 82(4):440–3. DOI: 10.1007/s00128-009-9661-4
Lee, R.J., Van Orden, D.R., 2007. Airborne asbestos in buildings. Reg. Toxi. and Pharm. 50(2), 218–25. DOI: 10.1016/j.yrtph.2007.10.005
Burdett, G.J., Dewberry, K., Staff, J., 2016. Airborne Asbestos Exposures from Warm Air Heating Systems in Schools. Ann. Occup. Hyg. 60(10), 27–39, https://doi.org/10.1093/annhyg/mev062
Upton, A.C., 1991. Asbestos in Public and Commercial Buildings - A literature revive and synthesis of current knowledge, Health Effect Institute - Asbestos Research. Cambridge. https://www.healtheffects.org/publication/asbestos-public-and-commercial-buildings
Reynolds, S.J., Kreiger, R.A., Bohn, J.A., et al., 1994. Factors affecting airborne concentrations of asbestos in a commercial building. J. Occup. Environ. Hyg. 55(9), 823–828. https://doi.org/10.1080/15428119491018547
Kakooei, H., Normohammadi, M., 2014. Asbestos exposure among construction workers during the demolition of old houses in Tehran, Iran. Ind. Health. 52(1), 71–77. DOI:10.2486/indhealth.2012-0118
Dumortier, P., De Vuyst, P., 2012. Asbestos exposure during uncontrolled removal of sprayed-on asbestos Ann. Occup. Hyg. 56(1), 49–54. DOI: 10.1093/annhyg/mer096
Chungsik,Y., Kiyoung, L., Park, D., 2011. Indoor air quality differences between Urban and preschools in Korea. Environ. Sci. Pollut. Res. Int. 18(3),333 – 45. DOI: 10.1007/s11356-010-0377-0
SRC. Inc Denver. CO Summary of Published Measurements of Asbestos Levels In Ambient Air Prepared for USA EPA, 2013
Darcey, D.J., Feltner, C., 2014. Occupational and environmental exposure to asbestos in Pathology of Asbestos-Associated Diseases, Third Edition, ed. Oury T. D., Sporn T. A., Roggli, V.L. https://doi.org/10.1007/978-3-642-41193-9_2
Obmiński, A., 2017. Asbestos in buildings, Scientific Studies, Warsaw (in Polish)
Obmiński A., 2009. Asbestos dust hazards during the dismantling of asbestos-containing products (indoors and outdoors), in Seminar: "Risk assessment of buildings contaminated with asbestos dust and risk control methods" Warsaw-ITB, 13–14 October
ECHA, 2021. Scientific report for evaluation of limit values for asbestos at the workplace Prepared by the European Chemicals Agency 1 February [Google Scholar]
Obmiński, A., 2022. The natural reduction of threat in selected systems of old buildings containing asbestos, Sci. Rep. 12, 2580 https://doi.org/10.1038/s41598-021-044877-y
Obmiński, A., 2021.The concentration of asbestos fibres during building exploitation analysis of concentration variability, Archiv. of Civ. and Mechan. Eng. 22(6). https://doi.org/10.1007/s43452-021-003203-2
Szeszenia-Dąbrowska, N., Świątkowska, B., et al., 2016. Environmental asbestos pollution - Situation in Poland. IMP, Łódź. https://doi.org/10.2478/s13382-012-0003-0
Moteallemi, A., et al.,2020. Monitoring of airborne asbestos fibres in urban ambient air of Mashhad City, Iran: levels, spatial distribution and seasonal variations. J. of Environ. Heal. Sci. and Engi. 18(1),1–8. DOI: 10.1007/s40201-020-00541-5
Ilgren, E.B., et al., 2015. Kandovan the next ‘Capadoccia’? – A potential public health issue for erionite-related mesothelioma risk. Epidemiology, Biostatistics, and Public Health (EBPH). 12(1). DOI: https://doi.org/10.2427/10106
Obmiński, A., 2020. Asbestos in building and its destruction, Con. Build. Mat. 249 https://doi.org/10.1016/j.conbuildmat.2020.118685
ITB Research Procedure PB LS-020/1 / 08-2006. Determination of the numerical concentration of asbestos-respirable fibres in building objects. Indoor air and atmospheric air. Optical microscopy method (in phase contrast and polarized light), 2006).
ITB (2006) Research Procedure PB LS-020/1/08-2006. Determination of the numerical concentration of asbestos-respirable fibres in building objects. Indoor air and atmospheric air. Optical microscopy method (in phase contrast and polarized light). PCA (Polish Center for Accreditation) Accreditation Certificate No. AB 023 (from 2006 up to 2022)
Chesson, J., Rench, J.D., Bradley, D., et al., 1990. Interpretation of airborne asbestos measurements. Risk Anal. 10(3), 437 – 47. https://doi.org/101111/j.1539-6924.1990.tb00527.x
Verma, D.K., Clark, N.E., 1995. Relationship between phase contrast microscopy and transmission electron microscopy results of samples occupational exposure to airborne chrysotile asbestos. Am. Ind. Hyg. Assoc. J. 56(9), 866–873. https://doi.org/10.1080/15428119591016494
TRGS 519 (1993), Asbestos Demolition work, repair and maintenance of asbestos-containing materials. Newsletter for the Rhineland-Wstwall.
Price, B. Crump, K.S., Baird, E.C., 1992. Airborne asbestos levels in buildings: maintenance worker and occupant exposures. J. Expo. Anal. Environ. Epidemiol. 2(3), 357–74.
Obmiński A. Analysis of Soil Contamination with Asbestos in Antropopressive Areas, Library of the Faculty of Earth Sciences, University of Silesia, Sosnowiec, (Doctoral dissertation) (1998)
Hodgson, J., Darnton, A., The quantitative risks of mesothelioma and lung cancer in relation to asbestos exposure Ann Occup Hyg 2000;44(8):565–601.
Curtis W. Noonan. Environmental asbestos exposure and risk of mesothelioma ATM Annals Translational Medicine Vol 5, No 11 (2017)
Rengyi Xu at al. Association between mesothelioma and non-occupational asbestos exposure: systematic review and meta-analysis Environmental Health vol. 17, Article number: 90 (2018)
Brown, S.K., 2017. Indoor air quality activities in Australia. Ind. and Buil. Environ. SAGE J., 26 (1). https://doi.org/10.1177/1420326X16675663

The data from this case was partially used in the author's previous article [30] to presentation " Changes in air pollution of three buildings type “LIPSK” within 48 weeks" .
Regarding German regulation [34] the required fiber concentration limit after ACM removal is 500 [F / m³].

No competing interests reported.

Environmental pollution as a result of a vacuum deficit in the working areas during asbestos removal work.

Status:

Journal Publication

Version 1

Abstract

Figures

Synopsis

1. Introduction

2. Materials - Analyzed cases of works

3. Methods

4. Test results

σ

5. Comparison of results and Discussion

6. Conclusions

Declarations

References

Footnotes

Additional Declarations

Supplementary Files

Status:

Journal Publication

Version 1