Batik workers are typically exposed to chemical hazards in the batik industry either from the air, waste water, or synthetic dye used in batik processing. In this study, we found that all of the chemical parameters of batik waste in Lendah were higher compared to the standard value of batik waste as mentioned in the Results section. Based on the WHO air quality guidelines, the excess concentration of PM 2.5 was only found in the pelorodan room . This condition is due to the use of firewood as the main source of heat to remove malam wax from batik materials. The combustion of firewood results in the formation of particulates which can affect workers’ health. In the other working areas, they used the Liquefied Petroleum Gas (LPG) as a source of heat so there were no combustion to generate particulates in the air, but there were PM 2.5 formed in aerosol from the vapor of melting malam.
In the three work spaces mentioned in the Results section, we found heavy metal contaminants in the work environment of the batik industry including Sulfur (S), Potassium (K), Titanium (Ti), Chromium (Cr), Manganese (Mn), Iron (Fe), Nickel (Ni), Zinc (Zn) and Lead (Pb). Despite those, the concentrations of heavy metal compounds in the work environment of the Batik Industry in Kulon Progo are small when compared to the threshold value of these compounds in the work environment referring to the regulation of the Minister of Manpower Republic of Indonesia No 5 of 2018 on Occupational Safety and Health of the Work Environment .
We also measured the heavy metal contaminants in the air inhaled by batik workers besides in the work area. Al, Fe, Cu and Zn had the highest concentrations of metal elements in the breathing zone. Levels of Al, Fe and Zn were within Indonesia, American Conference of Governmental Industrial Hygienists (ACGIH), National Institute for Occupational Safety and Health (NIOSH), and Occupational Safety and Health Administration (OSHA) limits, while the mean Cu levels in the breathing zone were above the regulation allowable limits [13, 14]. The synthetic dye used in batik also contains Pb, Cr, and Zn . The use of synthetic batik dyes containing heavy metals such as Pb and Cr are more popular because these substances can produce more beautiful and attractive colors .
Industrialization in the batik industry and higher demand of batik production, while important for the economic growth and development of a society, can be harmful for the environment especially with the use of synthetic dye. Although there are already many kinds of natural batik dye, the batik industry in Indonesia still uses the synthetic dyes that contain heavy metals. Those heavy metals will not only harm the environment but also be harmful for humans, especially the batik workers. Many batik workers primarily working in the dyeing process were exposed to Cr, a known carcinogenic and toxic substance. Besides that, we still found inadequate disposal of the waste in the batik industry.
In this study, we found no significant differences in blood Cr level between batik workers and control group. Despite the result, Cr is one of the eight metals in the top 50 priority list for toxic substances by the Agency for Toxic Substances and Disease Registry (ATSDR 2003). The majority of Cr in the environment exists in two valence states: trivalent chromium Cr(III) and hexavalent chromium Cr(VI). Batik workers may be exposed to Cr by breathing, eating, or drinking the substance, or by skin contact .
Cr(III) is generally benign due to poor membrane permeability. These compounds are even recognized as essential micronutrients that are involved in important physiological functions, such as the biological activity of insulin. In contrast, Cr(VI) compounds can actively penetrate cell membranes. Hexavalent chromium is a strong oxidizing agent and can lead to oxidative stress and DNA damage . Adverse health effects associated with Cr(VI) exposure include occupational asthma, eye irritation and damage, perforated eardrums, respiratory irritation, kidney damage, liver damage, pulmonary congestion and edema, upper abdominal pain, nose irritation and damage, respiratory cancer, skin irritation, erosion and discoloration of the teeth .
In this study, we found significant differences in liver and renal function tests between batik workers and non-batik workers (p < 0.05). There were higher values of liver and renal function tests in batik workers compared to control but still in the normal range. When the renal function tests are found abnormal, the nephropathy has already reached the irreversible phase that may lead to renal insufficiency . SGOT and SGPT have been used to show the status of liver functions. SGOT is an enzyme involved in the transfer of an amino group from aspartate. SGPT is an enzyme involved in the transfer of an amino group from alanine and present in the cytoplasm. SGPT is found in various tissues but is most commonly associated with the liver. Therefore, SGPT is a good biomarker of hepatocellular injury. Increased SGOT and SGPT are biomarkers of hepatic injury rather than hepatic dysfunction .
Urea is a waste product from protein breakdown in human liver and removed from our body through kidneys. Chromium are accumulated higher in renal cortex than red blood cells or liver and tend to damage kidneys. Higher urea levels usually indicate kidney damage. Negative correlation between blood Cr and urea may happen because Cr has no effect on that parameter, but this does not exclude kidney damage. Recently, many biomarkers are found to be correlated with kidney damage [25, 26].
There was a positive correlation between blood Cr level with SGOT, SGPT, and creatinine, but this result was not significant statistically. We proposed that the elevation of kidney and liver function values may be correlated to the exposure of heavy metals in occupational settings. These results demonstrated and supported that environmental and health interventions need to be done in the batik industry to prevent occupational diseases especially caused by heavy metal exposure.
As a solution, we developed the wastewater treatment plant using ss/graphene electrodes to create a more effective and environmentally friendly wastewater disposal system. The electro degradation process of dye by using ss/graphene electrodes is sufficient to remove color in a short amount of time, as little as 15 minutes (data published elsewhere).
Synthetic dyes used in the batik making process are naphthol, indigosol, rapid and ergan sogan dyes. Rapid dye is a stabilized combination of naphthol and diazonium, usually used for red color. The color generator used was sulphuric acid and vinegar acid.
The use of PPE is required to protects workers by isolating partially or entirely all of their body parts from any hazardous potential from in the workplace .
The most commonly used glove material in Indonesian batik industry are polyvinyl chloride (PVC) and nitrile. Protective gloves are often being forgotten by workers in the dyeing section due to the convenience aspect and work quality results. Specifically, in the dyeing section, the use of gloves makes workers have a difficulty in spreading color evenly and precisely. The bare hand method is preferred by workers due to the thickness and rigidity of the gloves which can hinder the work process .
There are different kinds of material for chemical protective gloves, including neoprene, butyl, nitrile, fluorocarbon, latex, and also combination of those materials to improve performance . Polyvinyl chloride (PVC) gloves as a type of gloves recently used by Batik workers are the least expensive of all materials and can be used as disposable gloves. PVC has high protection against nitric, chromic, and phosphoric acid. They are also resistant to aging. PVC is not recommended to be used against acetone, ketones, and ether since some concentrated acid can extract the plasticizer and harden PVC gloves, thus making them rigid .
Neoprene is the best for batik workers. Neoprene is made from synthetic rubber that is soft and able to fill in the gaps so that fingers can move freely, has high density and is resistant to tears. Neoprene gives strong protection from hydraulic liquids, fuel oil, alcohol and an organic base. Compared to rubber, neoprene gloves have better resistance towards chemicals and are not as easily worn out .
After collecting the reasoning of gloves scoring, several aspects were obtained, including: thickness, elasticity, breathability, coarseness (slipperiness), textured surface, length, starch, durability, and fitting. Gloves’ thickness play a prominent role as it is the main reason of why the subjects scored the test gloves higher than the PVC in statement number 1. Neoprene gloves are thinner which allows workers to handle the work products more firmly with less barrier. Thicker gloves as in PVC gloves would decrease workers’ manual dexterity and cause fatigue due to the higher muscle resistance. Thicker gloves can affect the breathability and may cause more sweat production due to a humid environment . Neoprene gloves are more elastic than the PVC gloves which allows the workers to control hand movement and have less fatigue . Elastic gloves also have decreased tightness because they will eventually adapt to workers’ hands sizes.
The next aspects are the coarse property and the textured surface on palm area of the neoprene gloves. Neoprene gloves’ characteristics would prevent the cloth from sliding over. Coarse material and textured surface would result in higher friction value against the cloth that would increase handgrip of the product thus increasing handling and mobility performance . The workers stated that the test gloves are coarser and had a more textured palm area that allowed better grip. This condition made the workers score the test gloves significantly higher in statement number 8.
Length of glove was a prominent aspect that affects convenience. Neoprene gloves’ length, which only reach to half of the workers’ lower arm, is inadequate to protect their hands while dyeing batik. This condition allows the dyeing infiltrate inside the gloves while dipping the cloth, making the gloves' function futile in protecting workers from the hazardous substance. Although only mentioned by three workers, the rubber band in the cuff of the PVC gloves also helped prevent the water from infiltrating inside the gloves. Workers stated that starch can cause an itchiness, foul smell and make the gloves more slippery. Starch is considered as an irritant agent to workers hands and can induce type 1 hypersensitivity reactions and occupational asthma . The high durability gloves would provide workers better safety, less worry, thus increasing their convenience. The durability of the gloves is influenced by heat and pH. They are often associated with thicker gloves and the type of material itself. Gloves’ tensile and elongation also play an important role in durability . The last aspect that influences convenience is gloves’ fitting. Workers prefer hand gloves that fit tight on the fingers area and loosely on the wrist. According to the interview, the test gloves (neoprene) have higher means score than PVC, but the result was not statistically significant.
The ideal gloves according to the workers are gloves that are thin but durable, length reached the elbow with rubber band on the cuff area, elastic, coarse on the outer layer, had textured surface on the palm area, fit on the fingers and loose on the wrist. Overall the workers feel the neoprene gloves are more comfortable than the PVC gloves and had already covered most of the ideal aspects except that the test gloves length’s is not adequate.
Convenience is an essential aspect of wearing gloves. Comfortable gloves would motivate workers to wear them correctly and in an orderly manner. Gloves are essential to be worn since the batik industry's chemical substances consist of many hazardous compounds that may be irritative, toxic, and even carcinogenic. Gloves that are worn correctly would help protect the workers from many hazardous compounds . Other than safety, comfortable gloves, or PPE would also help increase workers' productivity and the product's quality. This would also affect the increase of production rate, which is beneficial for both the home industry and the workers . However, high convenience gloves sometimes cost a higher price. In this case, neoprene is used less frequently in the industry due to the higher cost value. In the market, neoprene gloves' price range from Rp 70.000,00 to Rp 90.000,00. This is considered a high difference compared to the PVC gloves, ranging from Rp 20.000,00 to Rp 30.000,00.
Due to this matter, many textile industries that involve chemicals eventually use nitrile gloves. This is because the nitrile gloves have decent protection against textile chemicals, even though not as good as neoprene, but still have a reasonable price slightly higher than PVC . In the market, nitrile gloves' price ranged from Rp 30.000,00 to Rp 40.000,00. Due to this reason, nitrile gloves are often used as a solution to facilitate both safety and costs. However, the batik dye workers did not feel the nitrile gloves to be comfortable due to the presence of coating material on the inner of the glove, which can cause discomfort. One of the batik home industries as a subject of our study, Batik Farras, provide their workers with PVC gloves and rarely nitrile gloves since PVC are cheaper than nitrile gloves. If the three gloves are being compared, neoprene, even with the higher price, had the best tear-resistance and durability against the chemical, making it more durable and can be worn for a longer duration, therefore, needing less frequent of changing due to breakdown .
Carpal Tunnel Syndrome (CTS)
Carpal Tunnel Syndrome (CTS) occurs when the median nerve in the wrist is irritated and compressed. This event often happens in people who frequently do repetitive hand and finger movements. The wrist splints used in CTS patients at night for several weeks aims to keep the joint in a neutral position. Usually, CTS symptoms worsen at night because the hand tends to flex during sleep, and this could be prevented with wrist splint use .
Meanwhile, nerve gliding is a stretching technique that moves the neck and upper extremity through a specific range of motion to free the nerves and increase mobility. Nerve gliding will work well if done together with other adjuvant therapies . Nerve gliding can fix nerve pathways, decrease adhesion, improve nerve oxygenation and decrease pain due to ischemia .
A study conducted by Schmid et al. found that use of splinting or nerve gliding for one week could decrease the signal intensity from the median nerve in CTS patients, which was considered as a result of the decrease in intraneural edema. The average decrease in signal intensity was 11%, in addition to slight improvement in symptoms and function (p < 0.004) . Seradge et al. also showed that nerve gliding exercises could directly decrease pressure in the carpal tunnel pressure for CTS patients. Improvement in CTS clinical outcome by adjunct non-surgical treatment can result in significant savings in human suffering, medical cost, lost work time, and socioeconomic distress .
From the results of this study, we can see that nerve gliding exercises as well as wrist splints can cause apparent improvement in CTS clinical symptoms from week I to IV, but they did not show statistically significant difference in decreasing the number of CTS cases.
Social And Public Health Intervention
Based on the results, for the economic dimension, the financial feasibility of the batik industry needs to be maintained by improving business management quality and access to financial institutions. As for the social dimension, efforts to establish labor unions need to be put in place to mediate potential conflicts and improve service for workers, for example, by continuing efforts for occupational health campaigns. Lastly, for the ecological dimension, the quality and implementation of liquid waste treatment plans need to be improved so that the level of business and district-scale waste pollution can be controlled. The implication of these findings is that the existence of interest competition needs to be paralleled with efforts to help business owners to make choices based on substantial evidence to decide the steps that have to be taken to balance the sustainability of these three main pillars of the “Healthy Batik Village” area establishment (in detail, published elsewhere).