Elevated 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide concentrations in the household dust of farmers with recent occupational use

Abstract

Pesticide dust concentrations in homes have been previously associated with occupational and home/garden use of pesticides, hygiene practices, and other factors. This study evaluated the relationship between self-reported use of 2,4-dichlorophenoxyacetic acid (2,4-D) and house dust concentrations and these factors in the Biomarkers of Exposure and Effect in Agriculture (BEEA) Study, a molecular epidemiologic study of farmers in Iowa and North Carolina. The vacuum dust from the homes of 35 BEEA participants was analyzed for the presence of 2,4-D. Participants provided detailed information on occupational and home/garden pesticide use during the past 12 months and reported household characteristics via questionnaires. Linear regression models were used to examine the association between 2,4-D concentrations and four exposure metrics for occupational use in the last 12 months (yes/no, days since last use, days of use, intensity-weighted days of use), home/garden use (yes/no), as well as several household characteristics. 2,4-D was detected in all homes and was used occupationally by 54% of the participants. In a multi-variable model, compared to homes with no occupational or home/garden 2,4-D use reported in the past 12 months, concentrations were 1.6 (95% confidence interval (CI): 0.5, 4.9) times higher in homes with low occupational 2,4-D use (intensity-weighted days < median) and 3.1 (95% CI: 1.0, 9.8) times higher in homes of participants with high use (≥median intensity-weighted days) (p-trend = 0.06). Similar patterns were observed with other occupational metrics. Additionally, 2,4-D dust concentrations were non-significantly elevated (relative difference (RD) = 1.8, 95% CI: 0.5, 6.2) in homes with home/garden use and were significantly lower in homes that did not have carpets (RD = 0.20, 95% CI: 0.04, 0.98). These analyses suggest that elevated 2,4-D dust concentrations were associated with several metrics of recent occupational use and may be influenced by home/garden use and household characteristics.

Keywords:

• Agriculture
• dust sample
• farm
• occupational exposure
• pesticide
• vacuum dust

Acknowledgments

Amy Miller, Kate Torres, Emily Tristani, Linda Gowen, Himanshi Singh, Sarah Woodruff, Marsha Dunn, and other staff at Westat, Inc. (Rockville, MD) contributed to the study coordination and data management. We appreciate the field research team in Iowa, including Charles Lynch, Debra Lande, Debra Podaril, and Jennifer Hamilton. We thank the Southwest Research Institute (SwRI) who quantified the concentrations of herbicides in the dust samples and Alice Yau, who supervised the analyses. We also would like to thank Anne Taylor at Information Management Services, Inc. (Calverton, MD) for her help in preparing the research dataset. Finally, we gratefully acknowledge the participation of the Biomarkers of Exposure and Effect in Agriculture Study participants that made this work possible.

Conflicts of interest

The authors declare no conflict of interest relating to the material presented in this article. Its contents, including any opinions and/or conclusions expressed, are solely those of the authors.

Data availability statement

The data underlying this article will be shared on reasonable request to the senior author.

Additional information

Funding

This work was supported by the Intramural Research Program of the National Institutes of Health, National Cancer Institute, Division of Cancer Epidemiology and Genetics (Z01 CP 010119).