Correlates of organochlorine pesticide plasma concentrations among reproductive-aged black women

Abstract

Background: Organochlorine pesticides (OCPs) are lipophilic persistent organic pollutants associated with adverse health outcomes. Black women have higher body burdens compared with other U.S. populations and research on their correlates is limited.

Methods: Using baseline data from a prospective cohort study of Black women aged 23-35 years from the Detroit, Michigan metropolitan area (enrolled 2010-2012), we examined correlates of plasma concentrations of the following OCPs: dichlorodiphenyltrichloroethane (p,p'-DDE), hexachlorobenzene (HCB), oxychlordane, and trans-nonachlor. At enrollment, we collected non-fasting blood samples from 742 participants. We also collected data on demographic, behavioral, dietary, occupational, and medical history factors via self-administered questionnaires, telephone interviews, and in-person clinic visits. We fit linear regression models to calculate percent (%) differences across categories of each correlate and 95% confidence intervals (CIs).

Results: In models adjusted for all other correlates, a 5-year increase in age was associated with 24% higher oxychlordane (95% CI: 12%, 38%) and 26% higher trans-nonachlor (95% CI: 12%, 42%) plasma concentrations. Heavy alcohol use was associated with 7-9% higher plasma concentrations of p,p'-DDE, oxychlordane, and trans-nonachlor. Current smoking was associated with 10-19% higher plasma concentrations of all four OCPs, and was highest for current smokers of ≥10 cigarettes/day (% differences ranged from 22 to 29%). Compared with having never been breastfed during infancy, having been breastfed for ≥3 months was associated with 15% higher concentrations of p,p'-DDE (95% CI: 6%, 25%), 14% higher oxychlordane (95% CI: 5%, 24%), and 15% higher trans-nonachlor (95% CI: 5%, 27%). Consumption of ≥5 vs. ≤2 glasses/day of tap or bottled water was associated with 8-15% higher plasma concentrations of all four OCPs, and was highest for trans-nonachlor (% difference: 15%; 95% CI: 6%, 26%). No other dietary predictors were appreciably associated with plasma OCP concentrations. Obesity, parity, higher birth order, and longer lactation duration were inversely associated with plasma OCP concentrations.

Conclusions: In Black U.S. women of reproductive age, older age was an important correlate of plasma OCP concentrations. Exposure to OCPs earlier in life appears to contribute to current blood concentrations. In addition, tobacco, alcohol, and drinking water may be important sources of exposure.

Keywords: Black women; Chlordane; DDE; DDT; Pesticides.

Figure 1:. Adjusted percent differences and 95% confidence intervals in organochlorine pesticides by age, body mass index (BMI), alcohol use in the past year, and cigarette smoking status.

Abbreviations: p,p’-DDE= 2,2-Bis(4-chlorophenyl)-1,1-dichloroethene; HCB=Hexachlorobenzene. All x-axis are percent differences and 95% confidence intervals. All models use the log-transformed plasma concentrations as the dependent variable and include age, education, household income, occupation (farm or orchard, lawn care, or pesticides), cigarette smoking status, alcohol use, body mass index (BMI), birth order, breastfeeding history as an infant, parity, lactation history, early exposure to pesticides (maternal farm residence or work during pregnancy, and lived on or worked on a farm before the age of 18), fish intake, meat intake, poultry intake, dairy intake, egg intake, fruit intake, vegetable intake, water intake, and total caloric intake.

Figure 2:. Adjusted percent differences and 95% confidence intervals in organochlorine pesticides by history of breastfeeding in infancy, parity, lactation history, and order of birth.

Abbreviations: p,p’-DDE= 2,2-Bis(4-chlorophenyl)-1,1-dichloroethene; HCB=Hexachlorobenzene. All x-axis are percent differences and 95% confidence intervals. All models use the log-transformed plasma concentrations as the dependent variable and include age, education, household income, occupation (farm or orchard, lawn care, or pesticides), cigarette smoking status, alcohol use, body mass index (BMI), birth order, breastfeeding history as an infant, parity, lactation history, early exposure to pesticides (maternal farm residence or work during pregnancy, and lived on or worked on a farm before the age of 18), fish intake, meat intake, poultry intake, dairy intake, egg intake, fruit intake, vegetable intake, water intake, and total caloric intake.

Figure 3:. Adjusted percent differences and 95% confidence intervals in organochlorine pesticides by water intake (tap or bottled), and farm exposure in early life.

Abbreviations: p,p’-DDE= 2,2-Bis(4-chlorophenyl)-1,1-dichloroethene; HCB=Hexachlorobenzene. All x-axis are percent differences and 95% confidence intervals. All models use the log-transformed plasma concentrations as the dependent variable and include age, education, household income, occupation (farm or orchard, lawn care, or pesticides), cigarette smoking status, alcohol use, body mass index (BMI), birth order, breastfeeding history as an infant, parity, lactation history, early exposure to pesticides (maternal farm residence or work during pregnancy, and lived on or worked on a farm before the age of 18), fish intake, meat intake, poultry intake, dairy intake, egg intake, fruit intake, vegetable intake, water intake, and total caloric intake.