Grantee Research Project Results
2004 Progress Report: A Longitudinal Approach of Assessing Aggregate Exposure to Organophosphorus Pesticides in Children
EPA Grant Number: R829364Title: A Longitudinal Approach of Assessing Aggregate Exposure to Organophosphorus Pesticides in Children
Investigators: Lu, Chensheng (Alex)
Current Investigators: Lu, Chensheng (Alex) , Fenske, Richard
Institution: University of Washington
EPA Project Officer: Aja, Hayley
Project Period: September 1, 2001 through August 31, 2005
Project Period Covered by this Report: September 1, 2003 through August 31, 2004
Project Amount: $1,246,407
RFA: Aggregate Exposure Assessment for Pesticides: Longitudinal Case Studies (2001) RFA Text | Recipients Lists
Research Category: Pesticides , Safer Chemicals , Human Health
Objective:
The objectives of the research project are to:
- characterize the temporal and inter-individual variability of total organophosphorous (OP) pesticide exposures in children in relation to both residential pesticide use and dietary intake;
- examine children’s OP pesticide exposure from multiple sources via several unique pathways and assess the relative contribution of these pathways and sources to total OP pesticide body burden;
- and establish a baseline level of OP pesticide exposures in children and determine the contributions of OP pesticide residues on children’s diets to this baseline
Progress Summary:
During the past 12 months, four study sessions have been conducted, one during each season. The purpose was to create an exposure profile for each child during summer, fall, winter, and spring.
Subject Recruitment
Subject recruitment began in April 2003. After receiving permission from the Mercer Island School District, we contacted two elementary schools and the principals agreed to allow students to bring home flyers describing the research project. We also contacted a Montessori School on Mercer Island to reach parents of pre-school children, as our target age range was 2 to 12 years old. Interested parents contacted our office and answered a brief questionnaire to determine their eligibility. Twenty-three children were enrolled into the research project, and the age range of the subjects was 3 to 11 years.
During the month of June 2003, we met with each of the 23 families at their homes. We discussed the research project purpose and procedures with the families and answered their questions. They were given instructions and demonstrations of how to collect the saliva, urine, and food and juice samples. All of the 23 families agreed to participate and signed consent forms, which were approved by the University of Washington’s Human Subjects Division. The families were given the supplies for the study, which included saliva collection devices (Salivettes), food and juice collection bags and cups, urine collection cups, toilet pan inserts (if needed for collecting urine from young children), and a cooler and ice packs for storing the samples outside for pick-up by research staff. The parents also were given a food diary to fill out daily, a pesticide use questionnaire, a shopping list to complete for ordering organic groceries, and a calendar that detailed the study procedures to follow each day during the study period.
Summer Session: July–August 2003
This study session lasted 15 days. All 23 of the families contacted participated in this study session. Each day, the families collected urine and saliva samples from the children and recorded all the foods consumed by the children in the food diaries. On the first and last days of the study, four urine and four saliva samples were collected: one in the morning after waking up, one at lunch time, one at dinner time, and one before bed. During the other 13 days of the study, the families only collected saliva and urine samples twice a day: once in the morning and then before bed.
During the four4 urine and four saliva collection days, the families also collected duplicate diet items. If the children ate any fruit or vegetables or drank fruit juice on these 2 days, the families collected samples of these items. They placed the food in plastic storage bags and poured the juice into lidded cups. These items were labeled with the date and meal during which they were consumed.
During the first 3 days of the study the children consumed their regular diet of non-organic food, which is referred to as the conventional diet period. During the next 5 days of the study the children switched over to eating only organic food, except for dairy, soda, and meats. We provided each family with organic food for the 5-day period, which they selected from a shopping list. The families were advised not to change the children’s eating habits, but instead to replace the food they would usually eat with an organic substitute. During the final 7 days of the study the children stopped eating the organic food and resumed their conventional diets.
The families stored their children’s samples inside their refrigerators. Every morning they placed the samples in coolers with ice packs outside their homes for pick up. Samples were transported daily to the University of Washington laboratory for immediate processing and were stored in the freezer at –20 to –25ºC.
In this project session, 724 urine samples and 592 saliva samples were collected. They were sent to the Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia, for analysis. The samples are currently undergoing analysis for specific metabolites of OP and permethrin pesticides. The food samples were sent to the Washington State Department of Agriculture’s Plant Protection, Chemical, and Hop Lab in Yakima, Washington, for analysis. They were analyzed for pesticides, such as cis- and trans-permethrin, thiabendazole, methamidophos, acephate, diazinon, malathion, chlorpyrifos, phosmet, and azinphos methyl, which are included in the U.S. Department of Agriculture Pesticide Data Program.
Fall Session: October–November 2003
To make participation easier for the families, the second study session was shortened from 15 days to 12 days. Twenty-one of the study families agreed to participate in this session. One family declined to re-join the study because they were too busy to participate. The second family declined to participate because of personal difficulties not related to the study. Study procedures were identical to those used in the summer session, except for the collection of duplicate food sample day. During the conventional diet period, there was only one day when the families collected four urine and four saliva samples (one in the morning after waking up, one at lunch time, one at dinner time, and one before bed), as well as the 24-hour duplicate food items.
In this study session, 516 urine samples and 458 saliva samples were collected. They were sent to the CDC for analysis. Food samples were sent to the Washington State Department of Agriculture’s Plant Protection, Chemical, and Hop Lab for pesticide residue analysis.
Winter Session: February 2004
The purpose of this session and the next was to obtain children’s year-long pesticide exposure profiles in their urine and saliva. No dietary intervention was involved in these two sessions. This session lasted 7 days, with 20 of the families participating. One family declined to participate because their son didn’t want to collect his samples anymore.
The families collected urine and saliva samples twice a day from the children: one sample in the morning after waking up and one sample before bed. The parents also recorded all the foods consumed by the children in the food diaries. The children consumed their normal conventional diets during the entire period, and no food samples were collected.
In this study session, 268 urine samples and 225 saliva samples were collected. They were sent to the CDC for analysis.
Spring Session: May 2004
The fourth and final project session is currently underway. Nineteen of the families are participating in this 7-day session. One family did not return our phone calls and did not participate in this session. The families are collecting urine and saliva samples from the children twice a day: once in the morning and once in the evening before bed. The parents also are recording all the foods consumed by the children in food diaries. There is no organic diet intervention period; the children are consuming their normal conventional diets during the entire period.
In this final study period, 257 urine samples and 211 saliva samples have been collected. They will be shipped to the CDC for analysis upon completion of the study session.
All four study sessions have been very successful. Nineteen of the 23 original families were able to complete all four study sessions. All families have expressed their interest in this study and learning about the results.
Future Activities:
The data from the food analysis, food diaries, and pesticide use questionnaires have been entered into spreadsheets and are undergoing analysis. The results for the pesticide metabolite data from the CDC should be arriving soon.
Journal Articles:
No journal articles submitted with this report: View all 29 publications for this projectSupplemental Keywords:
toxic chemicals, children’s health, epidemiology, risk assessment, pesticides, age related differences, biological markers, children, dietary exposure, environmental hazard exposures, insecticides, organophosphate pesticides, pesticide exposures,, RFA, Health, Scientific Discipline, Air, Toxics, air toxics, pesticides, Risk Assessments, Susceptibility/Sensitive Population/Genetic Susceptibility, Biochemistry, Children's Health, genetic susceptability, pesticide exposure, rural communities, urban air, sensitive populations, monitoring, organophosphates, multi-pathway study, long term exposure, age-related differences, dermal contact, exposure, children, longitudinal study, gender-related variability, pesticide residues, insecticides, human exposure, environmental toxicant, neurotixics, dust , biological markers, dietary exposure, agricultural community, organophosphate pesticides, exposure assessment, environmental hazard exposuresProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.