Background:
Assessment of children’s exposure to chemicals may be different than for adults because children differ physiologically from adults in many ways. They have a larger surface area than adults; making children more susceptible to dermal exposure. They breathe more air and consume more food per body size and their rates of metabolism may also differ. Aside from physiological differences, children also may differ in exposure pathways. In agricultural communities, the exposure pathways are more complex for children because they can be exposed to pesticides from playing in/near the fields or from residues in the home that were brought back by the parents as well as from the traditional routes of inhalation, dermal absorption, and ingestion. Exposure to pesticides may be assessed by using biomarkers of exposure and tools such as surveys and observations may be used to identify the routes and pathways of exposure. In addition, the interaction of a child with his/her environment can be assessed by videotaping, time-activity diaries, and GPS systems. Few studies have examined the routes and pathways of pesticide exposure to children living in agricultural communities through visual time activity diaries. This tool is particularly useful because it can help identify critical pathways of exposure.
Project Description:
This study was in collaboration with Dr. Berna van Wendel de Joode who is with the Universidad Nacional of Costa Rica in Heredia, Dr. Christian Lindh from Lund University, Sweden, and Professor Brenda Eskenazi at UC Berkeley. The fieldwork took place in a small banana village that was sampled last year in Talamanca, Costa Rica. This village was chosen for this study because the children showed the highest amount of ethylenethioruea (ETU) in their urine from last year’s pilot study. ETU is the urinary metabolite of maneb and mancozeb, which are components of pesticides widely used in aerial spraying on banana plantations in Costa Rica.
This project will assess the activity patterns of young children (8-10 yrs old) by incorporating the use of a visual activity diary. A visual activity diary divides a 24 hr period into one-hour increments and is composed entirely of pictures to promote simplicity and clarity in completing the diary by the children. All the students that participated in last year’s study were eligible to participate in our study if they desired to. In total, we had 37 students, about half boys and half girls. The students were all trained on how to complete the survey during a pilot training for 3 days. A week after the pilot study, students continued to complete the visual time activity diary for 7 consecutive days. Colleagues from the Lund University also collected daily urine samples from the children to measure the levels of ethylenethiourea (ETU).
Objectives:
- Assess children’s activity levels to find out if they were engaged in quiet play or active play.
- Assess location of their activities, whether they are inside or outside and if they are outside, determine if they are in the banana plantation.
- Determine if children that spend more time outside engaged in active play have higher levels of ETU in their urine.
- Determine if there is a difference in activity levels or ETU levels between gender and/or age.
- Determine if the children are able to accurately complete the visual time activity survey.
Methods:
- Conduct initial observations to redesign a time activity survey to fit the culture of the banana community.
- Teach the children how to accurately complete the survey.
- Conduct spot observations to make sure the survey answers were validated.
Fieldwork Experience:
One of the biggest challenges to designing a visual time activity for children of this particular community is creating a survey that fits their cultural practices. For example, many children do not have watches and their concept of time is based on the sunrise and sunset so it was difficult for them to remember to fill out a survey every hour. However, buying them digital watches and teaching them how to use it resolved this issue. Also, there were pictures that represented a clear concept for me, but to the kids it meant something completely different. Another important point was to make sure that all the kids depicted in the pictures had black hair so that the children could relate to the pictures on the survey. Another issue was to figure out a way to remind the kids complete the survey daily and to not lose it during the course of their day. This particular banana village also receives extreme weather conditions daily in terms of excruciating heat or heavy downpours so the survey also had to withstand the weather.
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An example of the aerial spraying via helicopter. The helicopter sprayed directly over the school soccer field where the kids were playing after school.
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Taking all these factors into consideration, the survey consisted of four laminated cards of 4 inches by 5 inches bounded together by a key chain ring at the top left corner. A cord was attached to a marker that was tied to the set of four cards and worn around the child’s neck. This design allowed the set of cards to withstand the extreme rain as well as allow the child to mark on the plastic survey with a marker. Wearing it around the neck reminded the child to complete the survey every hour.
A pilot study was carried for 3 days to serve as a training session to teach all the kids in the study how to complete the survey. The kids were trained in a group of 4-5 for about 30 minutes each. Then they were given practice surveys to complete for 2 full days to familiarize themselves with the tool. Each day, I went through the neighborhood reminding the children to wear the surveys around their necks as well as to check that they were completely it accurately. What I noticed was that many of the kids seemed to be very confused with the survey and many more simply did not participate. It was clear that the kids had not had enough training and many were also not very comfortable with us. The kids that were able to participate were either very enthusiastic or they had help from an older sibling in the family. After the pilot study, many changes were implemented to make the survey much simpler to complete. For example, more representative pictures were used to aid children that could not read with the survey completion.
During the final study, a majority of the kids received individual training for an additional 3-4 days. All the children improved significantly after additional training because they would return surveys that were correctly completed. The kids also began to ask me questions, which signified that they were interested and engaged in the project. I further motivated the children to complete the project by announcing in the middle of the week that there would be a secret prize for the children that completed the surveys. This idea worked well because more kids were reminding each other to complete the survey and some even reported to me when they noticed a classmate had made a mistake. I also did daily spot observations to the children’s activity and location to make sure their answers were legitimate.
The key factors for success in a project like this is to build enthusiasm in the children and let them think that they are very important and special for participating in this study. There were children that could not read and did not seem to understand the survey in the beginning of the study. But after I spoke to the family members and asked the old siblings for help, those children showed a significant improvement. The age and gender of the child is no indication of how well he/she can participate in completing the survey. It has to do with how well the children can connect with the field worker and if the field worker can instill enthusiasm in the children.
The next steps for this project include conducting a statistical analysis on the data collected from the children’s surveys as well as correlating the activity levels and locations to the levels of metabolites in the urine.
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