Study Population and Setting
This study is a pre-post intervention study nested in a longitudinal study of adolescent and young adult pesticide applicators in Egypt. The original longitudinal study started in 2014 and continued to 2017, with follow up testing in 2018 and 2019. Adolescents under the age of 19 who worked for the Ministry of Agriculture to spray pesticides to cotton in the Nile delta were recruited in 2014 and 2015 from four field stations (Quesna, Shohada, Tala, and Berket El-Sabe’) in Menoufia Governorate, Egypt. The intervention was also available to a subset of applicators who were part of a longitudinal study characterizing neurobehavioral performance and organophosphate pesticide exposure (n=13, 8.4%) (14). Results where replicated excluding these individuals and no difference in the results were found. Applicators had the following job responsibilities surrounding pesticide use: mixing pesticides, filling backpack sprayers, and application of pesticides.
Agriculture is one of the largest employers in Egypt (18). The primary agricultural product in Egypt is cotton and because of its national economic importance, the use of pesticides on that crop is highly regulated by the Egyptian Ministry of Agriculture (MOA) (19). The national government purchases and sells the country’s entire cotton production and once farmers agree to plant cotton, applications of chemicals on those fields come under control of the Ministry of Agriculture. Thus, all pesticides, equipment and calibration procedures are standardized across the Governorate. Adolescents are hired by the MOA as seasonal workers to apply pesticides and may work for repeated seasons.
To assess pesticide application and hygiene behaviors of pesticide applicators, observational checklists of pesticide application were completed in August 2016 and August 2017. Observational checklists included personal protective equipment worn before and during pesticide application, mixing procedures, and hygiene after pesticide application. In May of 2017, in-between the two observational checklist dates, an intervention was completed training participants on the dangers and potential preventative measures around the application of pesticides.
In total, 119 study participants attended the intervention training in May 2017. Of these participants, 87 had completed observational checklists of pesticide application during August 2016 and 92 had observational checklists completed during August 2017. There were a total of 71 participants that completed the intervention training and had observational checklist data for 2016 and 2017. A follow-up to the intervention questionnaire was administered 8 months post intervention in which 95 individuals responded. Consent of human subjects was obtained from participants and procedures approved by the University of Iowa Institutional Review Board and the Medical Ethics Committee at Menoufia University.
Intervention Description and Risk Behavior Scale
We worked with the MOA to identify feasible and appropriate methods to reduce pesticide exposure. Initial workplace observations had identified behaviors during mixing, loading, and applying pesticides that increased adolescents contact with pesticides (e.g., mixing with hands, contact with pesticides during loading and applying, reentry into sprayed fields), and therefore exposure. In addition, self-reported hygiene practices indicated variability in time to change clothes or bathe after applying pesticides. We also found that increased urinary metabolite levels were associated with increased time applying, and lower urinary metabolite levels were associated with bathing immediately after work and using a stick to mix pesticides (instead of hands) (20). Focus groups held separately with officials from the MOA, adolescents, and parents presented study findings and discussed feasible methods to reduce exposure during application. We found that, while some PPE is supplied by the MOA (masks, gloves, glasses), this is not enough for all workers and some workers had concerns about the quality and effectiveness of the supplied PPE. Although the MOA has adopted procedures to reduce exposure (e.g., point nozzle downward, maintain distance between applicators, consider wind direction when applying), applicators reported receiving no formal training. Most workers reported bathing after work, however, there was variation in how frequently work clothes were washed (e.g., daily, monthly). The intervention incorporated feedback from the focus group in the intervention.
An intervention to train applicators on work and hygiene practices to reduce exposure was developed. Three behaviors were targeted: staying out of fields recently sprayed, using a stick (instead of hands) to mix pesticides, bathing/wearing clean clothes. Exposure reduction measures such as elimination or substitution of the hazardous substance or engineering out the exposure are considered superior methods of controlling exposure because they either prevent use of the hazardous substance altogether or control exposure at the source. When properly implemented, these methods can be effective regardless of worker interaction (21). While altering the targeted behaviors is less effective in reducing exposure than elimination or engineering controls, the goal of the intervention was to impact the direct activities taken by the adolescents themselves. This allows the adolescent to reduce their exposure to pesticides regardless of their workplace or available resources.
Participants of the intervention were surveyed on their views of pesticide safety and the effectiveness of targeted behaviors to reduce exposure to pesticides before and after the intervention, as well as, 8 months later to assess retention. The results were used to categorize individuals using the Risk Behavior Diagnosis (RBD) Scale based on pathways from the Extended Parallel Process Model (EPPM) (22, 23). The EPPM has been widely used in health promotion and disease prevention to develop interventions among diverse international populations (24-29).
The EPPM pathways identify how individuals are likely to control a health risk based on threat perception and efficacy of controlling that threat (23). These pathways have been used to group individuals into four quadrants of behavior using the RBD Scale: responsive (high threat-high efficacy), pro-active (high threat-low efficacy), avoidant (low threat-high efficacy), and indifferent (low threat-low efficacy) (30, 31). The questions used to assess threat and efficacy were related to the targeted behaviors of the interventions — mixing pesticides with a stick (not your hand), not entering fields, and hygiene around pesticide application. An average response of agree (4) on a 5 point scale of strongly disagree (1) to strongly agree (5) was used to place individuals into levels of high or low efficacy and high or low threat. Individuals were surveyed before the intervention, immediately following the intervention, and 8 months post intervention. In addition to the questions used to construct the RBD Scale, several questions about pesticide safety were asked at the same time periods.
Statistical Methods
Internal reliability of the RBD scale was assessed using Cronbach’s alpha coefficient. The scale was then used to place individuals into the four RBD quadrants of health risk behavior. Differences in demographics and pesticide application practices were compared across the quadrants using the Chi-squared test. Change in behavior post-intervention and 8 months later was compared using McNemar test to detect a difference in the proportion of individuals placed in each RBD quadrant. Similarly, changes in patterns of PPE used found during the 2016 and 2017 observational checklist and changes in feelings regarding pesticide safety were compared with McNemar test. Data analysis was completed with SAS 9.4 (SAS Institute, Cary, NC) with an alpha of 0.05 used for testing significance.