Development of a Web-based tool to collect and display water system customer service areas for public health action.

CONTEXT: Significant illness is associated with biological contaminants in drinking water, but little is known about health effects from low levels of chemical contamination in drinking water. To examine these effects in epidemiological studies, the sources of drinking water of study populations need to be known. OBJECTIVE: The California Environmental Health Tracking Program developed an online application that would collect data on the geographic location of public water system (PWS) customer service areas in California, which then could be linked to demographic and drinking water quality data. DESIGN: We deployed the Water Boundary Tool (WBT), a Web-based geospatial crowdsourcing application that can manage customer service boundary data for each PWS in California and can track changes over time. We also conducted a needs assessment for expansion to other states. SETTING/PARTICIPANTS: The WBT was designed for water system operators, local and state regulatory agencies, and government entities. RESULTS: Since its public launch in 2012, the WBT has collected service area boundaries for about 2300 individual PWS, serving more than 90% of the California population. Results of the needs assessment suggest interest and utility for deploying such a tool among states lacking statewide PWS service area boundary data. CONCLUSIONS: Although the WBT data set is incomplete, it has already been used for a variety of applications, including fulfilling legislatively mandated reporting requirements and linking customer service areas to drinking water quality data to better understand local water quality issues. Development of this tool holds promise to assist with outbreak investigations and prevention, environmental health monitoring, and emergency preparedness and response.

Hypospadias and residential proximity to pesticide applications.

BACKGROUND: Experimental evidence suggests pesticides may be associated with hypospadias. OBJECTIVE: Examine the association of hypospadias with residential proximity to commercial agricultural pesticide applications. METHODS: The study population included male infants born from 1991 to 2004 to mothers residing in 8 California counties. Cases (n = 690) were ascertained by the California Birth Defects Monitoring Program; controls were selected randomly from the birth population (n = 2195). We determined early pregnancy exposure to pesticide applications within a 500-m radius of mother's residential address, using detailed data on applications and land use. Associations with exposures to physicochemical groups of pesticides and specific chemicals were assessed using logistic regression adjusted for maternal race or ethnicity and age and infant birth year. RESULTS: Forty-one percent of cases and controls were classified as exposed to 57 chemical groups and 292 chemicals. Despite >500 statistical comparisons, there were few elevated odds ratios with confidence intervals that excluded 1 for chemical groups or specific chemicals. Those that did were for monochlorophenoxy acid or ester herbicides; the insecticides aldicarb, dimethoate, phorate, and petroleum oils; and adjuvant polyoxyethylene sorbitol among all cases; 2,6-dinitroaniline herbicides, the herbicide oxyfluorfen, and the fungicide copper sulfate among mild cases; and chloroacetanilide herbicides, polyalkyloxy compounds used as adjuvants, the insecticides aldicarb and acephate, and the adjuvant nonyl-phenoxy-poly(ethylene oxy)ethanol among moderate and severe cases. Odds ratios ranged from 1.9 to 2.9. CONCLUSIONS: Most pesticides were not associated with elevated hypospadias risk. For the few that were associated, results should be interpreted with caution until replicated in other study populations.

Spatially continuous local rate modeling for communication in public health: a practical approach.

A primary function of Environmental Public Health Tracking is the communication of spatial trends of diseases. Traditional (choropleth) approaches to disease mapping}?> have difficulty conveying intuitive understandings of the spatial continuity of disease risk, rate calculations in rural areas, and degrees of statistical significance. A spatial loess function can be utilized to depict continuous variations in preterm birth risk for the state of California on the basis of a 3-year birth cohort. Results from this function were graphically depicted and incorporated into a Web mapping service to maximize public accessibility. The function was evaluated as a tool for communication by considering its intuitive interpretation and comparing information derived from the function with that, which would be derived from a choropleth map using the same data. In general, the loess function was able to generate risk information for a variety of both urban and rural settings. Although richer in detail, this information was mostly consistent with that which would come from choropleth maps. Occasionally, information from the loess function stood in contradiction to the choropleth mapping procedure; however; we enumerate these occasions and discuss ways to maximize the consistency of the loess function with intuitive understandings of disease risk.

Maternal residence near agricultural pesticide applications and autism spectrum disorders among children in the California Central Valley.

BACKGROUND: Ambient levels of pesticides ("pesticide drift") are detectable at residences near agricultural field sites. OBJECTIVE: Our goal was to evaluate the hypothesis that maternal residence near agricultural pesticide applications during key periods of gestation could be associated with the development of autism spectrum disorders (ASD) in children. METHODS: We identified 465 children with ASD born during 1996-1998 using the California Department of Developmental Services electronic files, and matched them by maternal date of last menstrual period to 6,975 live-born, normal-birth-weight, term infants as controls. We determined proximity to pesticide applications using California Department of Pesticide Regulation records refined using Department of Water Resources land use polygons. A staged analytic design applying a priori criteria to the results of conditional logistic regressions was employed to exclude associations likely due to multiple testing error. RESULTS: Of 249 unique hypotheses, four that described organochlorine pesticide applications--specifically those of dicofol and endosulfan--occurring during the period immediately before and concurrent with central nervous system embryogenesis (clinical weeks 1 through 8) met a priori criteria and were unlikely to be a result of multiple testing. Multivariate a posteriori models comparing children of mothers living within 500 m of field sites with the highest nonzero quartile of organochlorine poundage to those with mothers not living near field sites suggested an odds ratio for ASD of 6.1 (95% confidence interval, 2.4-15.3). ASD risk increased with the poundage of organochlorine applied and decreased with distance from field sites. CONCLUSIONS: The association between residential proximity to organochlorine pesticide applications during gestation and ASD among children should be further studied.

Progress in pediatric asthma surveillance II: geospatial patterns of asthma in Alameda County, California.

INTRODUCTION: As with many diseases, the epidemic of asthma among children over the past few decades has been shaped by a social and environmental context that is becoming progressively more evident. Commonly used methods for asthma surveillance, however, are based on national rather than local data. The purpose of this study was to develop high-resolution asthma surveillance techniques responsive to the needs of health care professionals and local child health and social justice advocates. METHODS: We assembled a working data set of health care use records from 2001 from public and private sources covering 1.7 million person-months among children younger than 18 years in Alameda County, California. Health care use was categorized by type and analyzed by census tract demographic information. Images of the geographic distribution of health service events were created using density estimation mapping with overlapping 0.5-mile (805-m) radius spatial buffers, and statistical significance (two-tailed P & .05) was estimated using a Monte Carlo simulation algorithm. RESULTS: High-poverty communities had higher rates of emergency department visits due to asthma than low-poverty communities but had lower rates for indicators of quality primary asthma care. Geospatial analysis enabled visualization of this phenomenon; it further detected areas with elevated emergency department visit rates and potentially related environmental hazards in and around communities of concern. Areas of the county not previously considered to be deeply burdened by asthma were identified as having high emergency department visit rates. CONCLUSION: The assembly and high-resolution geospatial analysis of health care use data contributed to a more detailed depiction of pediatric asthma disparities than was previously available to community members, public health professionals, and clinicians. Information generated using these techniques facilitated discussion among stakeholders of the environmental and social contexts of asthma and health disparities in general. Proceedings of group evaluations suggested that the material aided in the translation of data describing spatial variations in health event risk to address specific community experiences and concerns.

Parental and birth characteristics in relation to testicular cancer risk among males born between 1960 and 1995 in California (United States).

OBJECTIVE: We explored birth and parental risk factors for testicular cancer, examining risk factors for all testicular cancers and by histologic type. METHODS: We linked 1645 testicular cancer cases to live singleton birth certificates, selecting three random controls per case, matched by sex and date of birth. We used conditional multiple logistic regression to assess the mutually adjusted effects of parental and birth characteristics on testicular cancer risk. RESULTS: Sons of Black mothers had a lower risk than those of White mothers (adjusted odds ratio (AOR) = 0.38, 95% confidence interval (CI)=0.12, 1.22). Increasing maternal age was associated with an increased risk in offspring (AOR=1.03 for each year of maternal age, 95% CI=1.01, 1.05). Sons of primiparous and low-multiparous women had increased risks compared to sons of high-multiparous women (AOR=1.22, 95% CI=1.04, 1.44; and AOR=1.31, 95% CI=1.12, 1.54, respectively). Among seminomas, term infants with birth weights of 1500-2499 g had a higher risk compared to term, normal birth weight infants (AOR=2.69, 95% CI=1.40, 5.17; p-value for homogeneity=0.008). CONCLUSIONS: Markers of higher estrogen exposure in the mother (age and parity) are associated with increased testicular cancer risk, and factors associated with fetal growth retardation may be associated with seminoma testicular cancer.