Elsevier

Environmental Research

Volume 109, Issue 7, October 2009, Pages 891-899
Environmental Research

Residential proximity to agricultural pesticide applications and childhood acute lymphoblastic leukemia

https://doi.org/10.1016/j.envres.2009.07.014Get rights and content

Abstract

Ambient exposure from residential proximity to applications of agricultural pesticides may contribute to the risk of childhood acute lymphoblastic leukemia (ALL). Using residential histories collected from the families of 213 ALL cases and 268 matched controls enrolled in the Northern California Childhood Leukemia Study, the authors assessed residential proximity within a half-mile (804.5 m) of pesticide applications by linking address histories with reports of agricultural pesticide use. Proximity was ascertained during different time windows of exposure, including the first year of life and the child's lifetime through the date of diagnosis for cases or reference for controls. Agricultural pesticides were categorized a priori into groups based on similarities in toxicological effects, physicochemical properties, and target pests or uses. The effects of moderate and high exposure for each group of pesticides were estimated using conditional logistic regression. Elevated ALL risk was associated with lifetime moderate exposure, but not high exposure, to certain physicochemical categories of pesticides, including organophosphates, chlorinated phenols, and triazines, and with pesticides classified as insecticides or fumigants. A similar pattern was also observed for several toxicological groups of pesticides. These findings suggest future directions for the identification of specific pesticides that may play a role in the etiology of childhood 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)

  • A. Bradman et al.

    Pesticides and their metabolites in the homes and urine of farmworker children living in the Salinas Valley, CA

    J. Expo. Sci. Environ. Epidemiol.

    (2007)
  • P.A. Buffler et al.

    Environmental and genetic risk factors for childhood leukemia: appraising the evidence

    Cancer Invest.

    (2005)
  • California Department of Pesticide Regulation, 2000. Pesticide Use Reporting: An Overview of California's Unique Full...
  • California Department of Pesticide Regulation, 2008. Summaries of Toxicology Data. California Department of Pesticide...
  • S.E. Carozza et al.

    Risk of childhood cancers associated with residence in agriculturally intense areas in the United States

    Environ. Health Perspect.

    (2008)
  • J.S. Chang et al.

    Parental smoking and the risk of childhood leukemia

    Am. J. Epidemiol.

    (2006)
  • T. Colborn et al.

    Developmental effects of endocrine-disrupting chemicals in wildlife and humans

    Environ. Health Perspect.

    (1993)
  • B.D. Curwin et al.

    Pesticide contamination inside farm and nonfarm homes

    J. Occup. Environ. Hyg.

    (2005)
  • B.D. Curwin et al.

    Urinary pesticide concentrations among children, mothers and fathers living in farm and non-farm households in Iowa

    Ann. Occup. Hyg.

    (2007)
  • J.L. Daniels et al.

    Pesticides and childhood cancers

    Environ. Health Perspect.

    (1997)
  • R.A. Fenske et al.

    Children's exposure to chlorpyrifos and parathion in an agricultural community in central Washington State

    Environ. Health Perspect.

    (2002)
  • K.R. Frost et al.

    Pesticide drift from aerial and ground applications

    Agric. Eng.

    (1970)
  • M. Harnly et al.

    Correlating agricultural use of organophosphates with outdoor air concentrations: a particular concern for children

    Environ. Health Perspect.

    (2005)
  • IARC (International Agency for Research on Cancer)

    Occupational exposures in insecticide application, and some pesticides

    IARC Monogr. Eval. Carcinog. Risk Hum.

    (1991)
  • Illinois Environmental Protection Agency

    Endocrine Disruptors Strategy

    (1997)
  • C. Infante-Rivard et al.

    Pesticides and childhood cancer: an update of Zahm and Ward's 1998 review

    J. Toxicol. Environ. Health B Crit. Rev.

    (2007)
  • C. Infante-Rivard et al.

    Risk of childhood leukemia associated with exposure to pesticides and with gene polymorphisms

    Epidemiology

    (1999)
  • J. Jurewicz et al.

    Exposure to pesticides and childhood cancer risk: has there been any progress in epidemiological studies?

    Int. J. Occup. Med. Environ. Health

    (2006)
  • Kegley, S.E., Hill, B.R., Orme, S., Choi, A.H., 2008. PAN Pesticide Database. Pesticide Action Network, North America,...
  • L. Keith

    Environmental Endocrine Disruptors: A Handbook of Property Data

    (1997)
  • D. Koch et al.

    Temporal association of children's pesticide exposure and agricultural spraying: report of a longitudinal biological monitoring study

    Environ. Health Perspect.

    (2002)
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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).

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