Residential proximity to agricultural pesticide applications and childhood acute lymphoblastic leukemia☆
Introduction
Previous case–control studies have observed an increased risk of childhood leukemia associated with household pesticide use and parental exposures to pesticides in occupational settings (Alderton et al., 2006; Belson et al., 2007; Buffler et al., 2005; Daniels et al., 1997; Infante-Rivard and Weichenthal, 2007; Infante-Rivard et al., 1999; Jurewicz and Hanke, 2006; Ma et al., 2002; Meinert et al., 2000; Menegaux et al., 2006; Monge et al., 2007). Agricultural pesticides applied near the home are another important source of exposure, particularly in rural communities. Pesticide concentrations in ambient air have been demonstrated to be higher in agricultural communities and near treated fields (Whitmore et al., 1994; Baker et al., 1996; Woodrow et al., 1997; Teske et al., 2002; Weppner et al., 2006). In studies of house dust measurements, concentrations of pesticide residues have been shown to be higher in residences closest to crops (Simcox et al., 1995; Lu et al., 2000; Fenske et al., 2002), in farm residences compared with non-farm residences (Curwin et al., 2005; Obendorf et al., 2006), and in residences with increasing acreage of crops within 750 m of the home (Ward et al., 2006). The few studies that have evaluated the association between proximity to agricultural pesticide use and childhood leukemia observed limited evidence for an etiologic relationship (Reynolds et al., 2005a, Reynolds et al., 2005b, Reynolds et al., 2002). These previous analyses only characterized pesticide use around a single residence at the time of birth or diagnosis, and thus did not account for multiple addresses during the subject's lifetime. Furthermore, these studies did not evaluate the effects of pesticide exposures during critical time periods such as gestation, the first year of life, or the child's lifetime from birth to the time of case diagnosis.
In this case–control study of childhood leukemia, we linked children's residential histories with available agricultural pesticide-use reporting data to characterize exposures to specific pesticides and groupings of pesticides during specific time periods of interest. We then examined whether residential proximity to agricultural applications of these agents is associated with acute lymphoblastic leukemia (ALL), the most common subtype of this childhood cancer.
Section snippets
Study population
The study population was derived from the first two phases of the Northern California Childhood Leukemia Study, an ongoing case–control study; the design of the study is discussed in detail elsewhere (Chang et al., 2006; Ma et al., 2004). Briefly, Phase I of the study consisted of cases diagnosed between August 1995 and November 1999 in one of 17 counties in the Greater San Francisco Bay Area. Cases in Phase II of the study were diagnosed between December 1999 and June 2002 in the Phase I area
Results
Table 2 lists the distributions of the matching factors and annual household income. Because subject eligibility for this analysis was limited to those born in or after 1990, all subjects were 10 years old or younger, with over half of the subjects under the age of five. Males accounted for 56% of the subjects, and 39% of the study subjects were Hispanic. The distribution of annual household income differed between case and control subjects with controls (38%) being more likely than cases (24%)
Discussion
We observed an increased risk of childhood ALL associated with moderate lifetime exposure to several categories of agricultural pesticides, including the target pest classes of insecticides or fumigants and the toxicological classes of probable or possible carcinogens, developmental or reproductive toxins, genotoxins, suspected endocrine disruptors, and anti-cholinesterases. Increased risks were not observed in the highest categories of exposure. A similar exposure–response pattern was observed
Acknowledgments and disclaimers
The authors thank the children and their families for their participation in the Northern California Childhood Leukemia Study, and clinical investigators at the collaborating hospitals for help in recruiting patients including University of California, Davis, Medical Center (Dr. Jonathan Ducore), University of California San Francisco (Drs. Mignon Loh and Katherine Matthay), Children's Hospital of Central California (Dr. Vonda Crouse), Lucile Packard Children's Hospital (Dr. Gary Dahl),
References (64)
- et al.
Isofenphos induced metabolic changes in K562 myeloid blast cells
Leuk. Res.
(2001) - et al.
Pesticide exposure of children in an agricultural community: evidence of household proximity to farmland and take home exposure pathways
Environ. Res.
(2000) - et al.
Organophosphate risk of leukemogenesis
Leuk. Res.
(2004) Expression of cholinesterases in brain and non-brain tumours
Chem. Biol. Interact.
(2005)- et al.
Chromosomal aberrations in human lymphocytes exposed to the anticholinesterase pesticide isofenphos with mechanisms of leukemogenesis
Leuk. Res.
(2004) - AgDRIFT Task Force, 1997. A summary of ground application studies. AgDRIFT Task Force, Macon, MO. Available from:...
- et al.
Child and maternal household chemical exposure and the risk of acute leukemia in children with Down's syndrome: a report from the Children's Oncology Group
Am. J. Epidemiol.
(2006) - et al.
Ambient concentrations of pesticides in California
Environ. Sci. Technol.
(1996) - et al.
Risk factors for acute leukemia in children: a review
Environ. Health Perspect.
(2007) - et al.
Cancer and developmental exposure to endocrine disruptors
Environ. Health Perspect.
(2003)
Pesticides and their metabolites in the homes and urine of farmworker children living in the Salinas Valley, CA
J. Expo. Sci. Environ. Epidemiol.
Environmental and genetic risk factors for childhood leukemia: appraising the evidence
Cancer Invest.
Risk of childhood cancers associated with residence in agriculturally intense areas in the United States
Environ. Health Perspect.
Parental smoking and the risk of childhood leukemia
Am. J. Epidemiol.
Developmental effects of endocrine-disrupting chemicals in wildlife and humans
Environ. Health Perspect.
Pesticide contamination inside farm and nonfarm homes
J. Occup. Environ. Hyg.
Urinary pesticide concentrations among children, mothers and fathers living in farm and non-farm households in Iowa
Ann. Occup. Hyg.
Pesticides and childhood cancers
Environ. Health Perspect.
Children's exposure to chlorpyrifos and parathion in an agricultural community in central Washington State
Environ. Health Perspect.
Pesticide drift from aerial and ground applications
Agric. Eng.
Correlating agricultural use of organophosphates with outdoor air concentrations: a particular concern for children
Environ. Health Perspect.
Occupational exposures in insecticide application, and some pesticides
IARC Monogr. Eval. Carcinog. Risk Hum.
Endocrine Disruptors Strategy
Pesticides and childhood cancer: an update of Zahm and Ward's 1998 review
J. Toxicol. Environ. Health B Crit. Rev.
Risk of childhood leukemia associated with exposure to pesticides and with gene polymorphisms
Epidemiology
Exposure to pesticides and childhood cancer risk: has there been any progress in epidemiological studies?
Int. J. Occup. Med. Environ. Health
Environmental Endocrine Disruptors: A Handbook of Property Data
Temporal association of children's pesticide exposure and agricultural spraying: report of a longitudinal biological monitoring study
Environ. Health Perspect.
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2022, Landscape and Urban PlanningCitation Excerpt :For instance, in our study area one research determined that urban populations of children do not suffer any evident genotoxicity associated with the use of pesticides, as long as they are located at distances greater than the range of 1500 to 2000 m (Bernardi et al., 2015). At the international level, numerous studies have determined adverse effects or increased health risks, pre and post-natal, in children living at different distances within 2000 m from fields sprayed with pesticides: cancer (Booth et al., 2015; Gómez-Barroso et al., 2016; Malagoli et al., 2016; Rull et al., 2006; Rull et al., 2009), neurodevelopmental disorders (González-Alzaga et al., 2015; Gunier Robert et al., 2017; Roberts et al., 2007; Rowe et al., 2016; Shelton et al., 2014), respiratory problems (Raanan et al., 2017), malformations (Benítez-Leite et al., 2009; Rull et al., 2006) and alteration of metabolites or biological markers (Babina et al., 2012; Coronado et al., 2011; Gómez-Arroyo et al., 2013; Lu et al., 2000). Another aspect that needs further investigation, which is fundamental to understanding possible contact with pesticide use, concerns natural or artificial barriers to spray drift from nearby fields.
Spatio-temporal variation of outdoor and indoor pesticide air concentrations in homes near agricultural fields
2021, Atmospheric Environment
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Funding support: This work was supported by the National Institute of Environmental Health Sciences (R01-ES09137) and the National Cancer Institute (R01-CA92674).