The Science and Safety of Atrazine: Scientific Conclusions

Residents of agricultural areas experience pesticide exposures from sources other than direct agricultural work. This Agricultural Health Study uses an algorithm for quantitatively estimating non-occupational pesticide exposure intensity for spouses...>>

Few studies evaluate the associations between pesticides and hyperthyroidism. This Agricultural Health Study evaluates associations between specific pesticides and incident hyperthyroidism in private pesticide applicators...>>

Reactive oxygen species can overwhelm an organism's antioxidant capabilities resulting in oxidative stress. This longitudinal study of atrazine and 2,4-dichlorophenoxyacetic acid exposure examines oxidative stress markers among Iowa corn farmers...>>

The occupation of farming has been associated with rheumatoid arthritis (RA); pesticides may account for this association, but few studies are available. This Agricultural Health Study investigates pesticide exposure and risk of RA among licensed male pesticide applicators...>>

Epidemiological evidence is limited. This Agricultural Health Study examines pesticide use and risk of end-stage renal disease among licensed pesticide applicators...>>

Endocrine-disrupting chemicals, including pesticides, may be associated with weight gain. This Agricultural Health Study examines pesticide exposures and body mass index of pesticide applicators...>>

No epidemiologic study has evaluated acetochlor’s carcinogenicity in humans. This Agricultural Health Study evaluates the use of acetochlor and cancer incidence among licensed pesticide applicators...>>

Few epidemiologic studies have provided evidence for an association between the atrazine mechanism in rodents and operation in humans. This Agricultural Health Study calculates atrazine and cancer incidence among pesticide applicators...>>

This longitudinal molecular epidemiologic study develops quantitative estimates of farmers’ pesticide exposure to atrazine and provides an overview of background levels of selected nonpersistent pesticides corn farmers during a growing season...>>

Biological monitoring is often employed to assess potential exposure to pesticides in farm children; however, the significance of exposure is uncertain unless doses are estimated. This study investigates pesticide dose estimates for children of Iowa farmers and nonfarmers...>>

Iowa farm and nonfarm households were recruited to participate in a study investigating take-home pesticide exposure. This study examines urinary pesticide concentrations among children, mothers and fathers living in farm and nonfarm households in Iowa...>>

This Agricultural Health Study examines the association between pesticide use during pregnancy and gestational diabetes mellitus among wives of licensed pesticide applicators...>>

This study investigates farm family pesticide exposure and home contamination based on urine and hand wipe samples collected from male farmers and nonfarmers in Iowa...>>

This study investigates agricultural pesticide contamination inside farm and nonfarm households...>>

Both animal and human studies have suggested that atrazine is possibly carcinogenic, but results have been mixed. This Agricultural Health Study evaluates cancer incidence in atrazine-exposed pesticide applicators in Iowa and North Carolina...>>

This study investigates differences in pesticide contamination and exposure factors between farm and nonfarm homes in Iowa...>>

Pesticides may contribute to respiratory symptoms among farmers. This Agricultural Health Study explores the association between wheeze and pesticide use among pesticide applicators in Iowa and North Carolina...>>

This study reviews conflicting reports from the EPA and the EPA Scientific Advisory Panel on the carcinogenicity of atrazine to determine whether the results from epidemiologic studies support a causal relationship between atrazine and any specific cancer. ..>>

Several studies suggest that the incidence of developmental and acquired abnormalities of the male urogenital system has increased. This report assesses the relationship between hypospadias and proximity to agricultural pesticide application in eastern Arkansas...>>

Evidence of an association between organochlorine exposure and thyroid disease is increasing. This Agricultural Health Study examines the cross-sectional association between the use of organochlorines and risk of hypothyroidism and hyperthyroidism among female spouses in Iowa and North Carolina...>>

This framework assessment examines the weight of evidence of biological plausibility and the epidemiological evidence for a causal relationship between atrazine exposure and the occurrence of breast cancer in women...>>

The epidemiologic evidence for an association between pesticides and gastroschisis is poor. An expert panel review cases of gastroschisis in the Northern Rivers area and find no evidence to support concerns of a higher rate of the condition in northern New South Wales...>>

Experimental research evaluating the potential ecological effects of atrazine vary in test species, methods and scientific rigor. This analysis, based on quantitative weight of evidence, evaluates the effects of atrazine on fish, amphibians and reptiles...>>

Improving the quality of pesticide toxicity studies is a shared goal in ecotoxicology. This strength of methods assessment using atrazine and testing on primary producers applies a transparent scoring system for assessing the quality of peer-reviewed studies...>>

The potential exposure of nontarget terrestrial plants to pesticides occurs via drift. This field-scale, spray drift study with atrazine measures spray drift deposition, airborne interception and corresponding biological effects on two sensitive plant species, cucumber and lettuce...>>

This hybrid individual-based and food web-ecosystem modeling approach assesses ecological risks posed by atrazine to the Topeka shiner. The model simulates Topeka shiner population and food web dynamics for an Iowa headwater pool...>>

Population models are important tools for pesticide risk assessment of nontarget species. This case study presents a population model for Mead’s milkweed, a species listed as threatened under the Endangered Species Act...>>

Extrapolating from organism‐level endpoints to populations is an important step in threatened and endangered species risk assessments. This population model for Boltonia decurrens estimates the potential population‐level impacts of three herbicides...>>

Aquatic exposure assessments using surface water quality monitoring data are often challenged. This evaluation uses a research data set near‐daily sampled site‐years from the Atrazine Ecological Monitoring Program...>>

Potential peak functions of annual pesticide concentrations in the aquatic environment are important exposure parameters for ecological risk assessments. This study examines stream flow as a covariate to improve predictions of maximum rolling averages and atrazine concentration in streams...>>

Understanding dermal exposure is important for higher-tier avian ecological risk assessments. This study conducts atrazine dermal absorption data experiments with mallard, northern bobwhite and rat skin to introduce a new approach for estimating and predicting exposure...>>

Short-term reproduction assays were conducted with fathead minnow and Japanese medaka in this study to evaluate responses from atrazine exposure at environmentally relevant concentrations...>>

Agricultural intensification has been suggested as a significant driver of bird population dynamics. This study examines the relationship by comparing bird count data in the central United States to corresponding categorical changes in land cover...>>

Although population models are recognized as necessary tools in the ecological risk assessment of pesticides, their application is limited. This study uses an individual‐based population model for threatened plant species, Boltonia decurrens, for application in pesticide risk assessment...>>

As part of registration review, the EPA revisited a community‐level of concern for atrazine that is protective of aquatic plant communities. This article reviews four methods that can or have been used for this purpose...>>

In this study, breeding groups of Japanese medaka are exposed to atrazine and evaluated endpoints related to survival, growth or reproduction are evaluated...>>

This study examines the performance of kriging methods in predicting maximum rolling averages of atrazine concentrations in 42 site‐years of Midwest Corn Belt watersheds...>>

This study performed a multiple‐pulsed atrazine experiment to measure responses of autotrophic endpoints in field-based stream mesocosms, synthetically simulating worst‐case atrazine chemographs from streams in agricultural catchments...>>

In this study, terrestrial plants were exposed to a direct overspray of atrazine according to EPA seedling emergence and vegetative vigor study guidelines and subsequently evaluated for potential recovery...>>

This study examines variation in toxicity of atrazine to a representative green algal species with changes in light intensity, water temperature, concentrations of nutrients or combinations of these parameters...>>

This study examines agroecosystem-derived lotic periphyton to assess variation in community sensitivity to and ability to recover from acute exposure to atrazine across sites and time and determines variables that are predictive for observed differences...>>

This study assesses the potential effects and ecological impacts of atrazine on nontarget aquatic plants characteristic of lower‐order streams in the Midwestern U.S. using comparative models...>>

The yellow-spotted salamander produces eggs that are colonized by a symbiotic green alga. This study tests the sensitivity of this system to atrazine...>>

In this study, the dynamics of periphyton, phytoplankton and environmental factors were monitored at agricultural streams in the Midwest. Variation partitioning of community models were used to determine the community inertia that is explained uniquely and/or jointly by atrazine...>>

This study characterizes, assesses and compares periphyton and benthic communities using standard collection methods and data from Midwest watersheds with varying historical levels of atrazine to evaluate possible differences or similarities among sites...>>

Studies have demonstrated the potential for impacts to salamander embryos when growth of the algae is impaired by exposure to herbicides. This study investigates the relationship by characterizing the response of symbiotic algae alone to atrazine under controlled laboratory conditions...>>

This study uses a survey sampling approach and its application to an atrazine groundwater monitoring study to adequately characterize upper exposure centiles and associated confidence intervals with predetermined precision...>>

This study develops sampling, storage and exposure methods for the consistent and effective characterization of acute response and recovery of field-derived periphyton to photosystem II inhibiting herbicides, particularly atrazine...>>

This study assesses the sensitivity of Pseudokirchneriella subcapitata to atrazine following a pulsed exposure that reflects amplifications of those observed in streams from highly vulnerable watersheds in regions of intense use...>>

In this study, a comprehensive aquatic systems model for atrazine estimates its potential toxic effects of on populations of aquatic plants and consumers in a generic lower‐order midwestern stream...>>

This exploratory study presents in situ observations of native algal communities relative to atrazine exposure and other parameters, conducted at sites in the midwestern U.S. where atrazine is commonly used...>>

In this study, a survey sampling approach is used to estimate upper centiles of aggregate distributions of surface water pesticide measurements obtained from datasets with large sample sizes but variable sampling frequency...>>

This study evaluates the recovery of duckweed after being removed from multiple duration exposures to the herbicide atrazine...>>

Light intensity can have an influence on the degree of phytotoxicity experienced by plants exposed to photosystem inhibiting herbicides. This study evaluates the relationship in submerged aquatic macrophyte Elodea canadensis exposed to different concentrations of atrazine and light intensities...>>

This study evaluates the recovery of photosynthesis and growth rate in green (Pseudokirchneriella subcapitata), blue‐green (Anabaena flos‐aquae) and diatom (Navicula pelliculosa) algae after pulsed exposure to atrazine...>>

In this study, Xenopus laevis tadpoles are exposed to atrazine concentrations in validated flow-through exposure systems to investigate growth, larval development and sexual differentiation...>>

This report examines potential modes of action for atrazine according to the criteria identified in the IPCS Framework for Analysing the Relevance of a Cancer Mode of Action for Humans and investigates a link between exposure and identified toxicological endpoints...>>

Using triazine herbicides as a case study, this report describes a method to use the AGSIM policy model to estimate changes in soil erosion and diesel fuel consumption for tillage that result from agricultural policy changes...>>

This report provides an economic assessment of the benefits of chloro-s-triazine herbicides atrazine, simazine and propazine to U.S. corn, sorghum and sugarcane producers...>>

This study compares atrazine doses that interfere with GnRH signaling seen in adult rats with doses that impair GnRH signaling in peripubertal rats, as indicated by delayed sexual maturation...>>

A better understanding of the mechanisms by which atrazine appears in surface waters can help inform water quality improvement. This study considers causal factors for trends in pesticide concentration in U.S. streams and models the causal factors in structural equation models...>>

Research conducted by Weed Science Society of America concludes that, if weeds were allowed to grow with no control measures, about half of U.S. and Canadian corn and soybean crops would be lost, costing growers $43 billion annually...>>

The ecology of amphibian intersex is poorly known. This report analyses the frequency of amphibian intersex across a range of land covers representing the major landscape types within a region...>>

This report discusses atrazine environmental levels and human exposure, kinetics and metabolism in laboratory animals and humans, a toxicological summary and practical aspects...>>

This report provides a detailed toxicological evaluation for eleven pesticides...>>

This review summarizes scientific studies related to atrazine and cancer epidemiology including a consideration of animal mode of action related to selected cancers...>>

This cumulative assessment estimates exposures and potential risks from current uses of chlorotriazine herbicides, including atrazine, propazine and simazine...>>

This review details an open literature search conducted for the triazines and the subsequent review of the studies gathered from the search...>>

This human health risk assessment of chlorotriazine herbicides serves to support the registration review of atrazine...>>

This white paper provides an overview of scientific literature and assesses the strengths and limitations of available studies to evaluate the extent to which atrazine may elicit developmental effects in amphibians...>>

This memorandum presents general information on the usage, pest management benefits and impacts of potential mitigation of these triazines in field corn production...>>

This white paper evaluates the food tolerances and cumulative risk from substances sharing a common mechanism of toxicity before reregistration is considered...>>

This document outlines the importance of water, sanitation and hygiene for health and development and issues guidelines to secure safe drinking water...>>

This document is a preliminary problem formulation for atrazine to fulfill registration review requirements under FIFRA...>>

This report evaluates data and regulatory decisions on the active ingredient atrazine, all products containing atrazine and associated labels...>>

To assist the EPA in refining the Preliminary Interim Decision for atrazine, comments and supporting documents were submitted related to benefits assessments, human health risk assessment and ecological risk assessment...>>

This report evaluates studies that investigate potential effects to human health risk assessment for atrazine to ensure EPA regulatory decisions continue to protect public health and the environment...>>

EPA oversight of atrazine includes its periodic re-evaluation through the registration review process. This page includes information on registration, monitoring in drinking water and ecological exposure monitoring...>>

This meeting summarizes studies focusing on the issues of carcinogenicity, endocrine disruption and immunotoxicity of atrazine. Reference is made to several reviews made by national and international agencies and organizations...>>

This special review of pest control products containing atrazine evaluates the potential for atrazine and its chlorinated transformation products to leach to groundwater...>>

This meeting re-evaluates the human health effects of atrazine and reviews noncancer effects, drinking water monitoring frequency and cancer epidemiology...>>