Evaluation of mortality among Marines, Navy personnel, and civilian workers exposed to contaminated drinking water at USMC base Camp Lejeune: a cohort study.

BACKGROUND: Drinking water at U.S. Marine Corps Base (MCB) Camp Lejeune, North Carolina was contaminated with trichloroethylene and other industrial solvents from 1953 to 1985. METHODS: A cohort mortality study was conducted of Marines/Navy personnel who, between 1975 and 1985, began service and were stationed at Camp Lejeune (N = 159,128) or MCB Camp Pendleton, California (N = 168,406), and civilian workers employed at Camp Lejeune (N = 7,332) or Camp Pendleton (N = 6,677) between October 1972 and December 1985. Camp Pendleton's drinking water was not contaminated with industrial solvents. Mortality follow-up was between 1979 and 2018. Proportional hazards regression was used to calculate adjusted hazard ratios (aHRs) comparing mortality rates between Camp Lejeune and Camp Pendleton cohorts. The ratio of upper and lower 95% confidence interval (CI) limits, or CIR, was used to evaluate the precision of aHRs. The study focused on underlying causes of death with aHRs ≥ 1.20 and CIRs ≤ 3. RESULTS: Deaths among Camp Lejeune and Camp Pendleton Marines/Navy personnel totaled 19,250 and 21,134, respectively. Deaths among Camp Lejeune and Camp Pendleton civilian workers totaled 3,055 and 3,280, respectively. Compared to Camp Pendleton Marines/Navy personnel, Camp Lejeune had aHRs ≥ 1.20 with CIRs ≤ 3 for cancers of the kidney (aHR = 1.21, 95% CI: 0.95, 1.54), esophagus (aHR = 1.24, 95% CI: 1.00, 1.54) and female breast (aHR = 1.20, 95% CI: 0.73, 1.98). Causes of death with aHRs ≥ 1.20 and CIR > 3, included Parkinson disease, myelodysplastic syndrome and cancers of the testes, cervix and ovary. Compared to Camp Pendleton civilian workers, Camp Lejeune had aHRs ≥ 1.20 with CIRs ≤ 3 for chronic kidney disease (aHR = 1.88, 95% CI: 1.13, 3.11) and Parkinson disease (aHR = 1.21, 95% CI: 0.72, 2.04). Female breast cancer had an aHR of 1.19 (95% CI: 0.76, 1.88), and aHRs ≥ 1.20 with CIRs > 3 were observed for kidney and pharyngeal cancers, melanoma, Hodgkin lymphoma, and chronic myeloid leukemia. Quantitative bias analyses indicated that confounding due to smoking and alcohol consumption would not appreciably impact the findings. CONCLUSION: Marines/Navy personnel and civilian workers likely exposed to contaminated drinking water at Camp Lejeune had increased hazard ratios for several causes of death compared to Camp Pendleton.

Evaluating the Effectiveness of State-Level Policies on Childhood Blood Lead Testing Rates.

CONTEXT: Lead exposure can harm nearly every organ in the human body. Millions of US children are exposed to lead hazards. Identifying lead-exposed children using blood lead testing is essential for connecting them to appropriate follow-up services. However, blood lead testing is not consistently conducted for at-risk children. Thus, determining which policies help improve blood lead testing rates is essential. OBJECTIVE: This analysis provides critical evidence to better understand which state-level policies are more effective at increasing childhood blood lead testing rates. These include metrics, incentives, other managed care organization guidance, provider guidelines, mandatory reporting of results to state health departments, data sharing between Medicaid and other state agencies, and proof of testing for school enrollment. DESIGN: This analysis included 33 states with complete data on the number of children tested for blood lead in 2017-2018 as reported to the Centers for Disease Control and Prevention. Linear regression modeling was conducted to examine associations between testing rates and the aforementioned policies. Fully adjusted models included percentages of the population living in pre-1980 housing, younger than 6 years with Medicaid coverage, and foreign-born. RESULTS: Strongest unadjusted and adjusted regression coefficients were observed for requiring proof of testing for school enrollment (ß = .12, P = .03) and metrics (ß = .06, P = .01), respectively. CONCLUSION: Policies associated with higher childhood blood lead testing rates can be used by policy makers; local, state, and federal public health agencies; professional organizations; nonprofit organizations; and others to inform development and implementation of additional policies to increase childhood blood lead testing.

Evaluation of contaminated drinking water and male breast cancer at Marine Corps Base Camp Lejeune, North Carolina: a case control study.

BACKGROUND: Solvents contaminated drinking water supplies at Marine Corps Base Camp Lejeune during 1950s-1985. METHODS: We conducted a case-control study among Marines to evaluate associations between residential exposure to contaminated drinking water at Camp Lejeune and male breast cancer risk. The study included 71 male breast cancer cases and 373 controls identified from the Department of Veteran's Affairs (VA) cancer registry whose military personnel records were available. Controls were selected from cancers not known to be associated with solvent exposure and included 270 skin cancers, 71 mesotheliomas, and 32 bone cancers. Base assignment and risk factor information came from military personnel and VA records. Groundwater contaminant fate/transport and distribution system models provided monthly estimated residential contaminant levels. We conducted exact logistic regression using the 50th percentile level among exposed controls to create low and high exposure categories. We calculated 95% confidence intervals (CIs) to indicate precision of effect estimates. Exploratory analyses used proportional hazards methods to evaluate associations between exposures and age at diagnosis. RESULTS: After adjusting for age at diagnosis, race, and service in Vietnam, the odds ratio (OR) for ever stationed at Camp Lejeune was 1.14 (95% CI: 0.65, 1.97). Adjusted ORs for high residential cumulative exposures to tetrachloroethylene (PCE), t-1,2 dichloroethylene (DCE), and vinyl chloride were 1.20 [95% CI: 0.16-5.89], 1.50 [95% CI: 0.30-6.11], 1.19 [95% CI: 0.16-5.89], respectively, with a monotonic exposure response relationship for PCE only. However these results were based on two or three cases in the high cumulative exposure categories. Ever stationed at Camp Lejeune and high cumulative exposures to trichloroethylene (TCE), PCE, DCE and vinyl chloride were associated with earlier age at onset for male breast cancer; hazard ratios ranged from 1.4-2.7 with wide confidence intervals for cumulative exposure variables. CONCLUSION: Findings suggested possible associations between male breast cancer and being stationed at Camp Lejeune and cumulative exposure to PCE, DCE, and vinyl chloride. TCE, PCE, DCE and vinyl chloride cumulative exposures showed possible associations with earlier age at onset of male breast cancer. However, this study was limited by small numbers of cases in high exposure categories.

Evaluation of contaminated drinking water and preterm birth, small for gestational age, and birth weight at Marine Corps Base Camp Lejeune, North Carolina: a cross-sectional study.

BACKGROUND: Births during 1968-1985 at Camp Lejeune were exposed to drinking water contaminated with trichloroethylene (TCE), tetrachloroethylene (PCE), and benzene. METHODS: We conducted a cross-sectional study to evaluate associations between residential prenatal exposure to contaminated drinking water at Camp Lejeune during 1968-1985 and preterm birth, small for gestational age (SGA), term low birth weight (TLBW), and mean birth weight (MBW) deficit. Birth certificates identified mothers residing at Camp Lejeune at delivery. We analyzed exposure data for the entire pregnancy and individual trimesters. For each period examined, births were categorized as unexposed if mothers did not reside at Camp Lejeune or if their residence on base received uncontaminated drinking water. Ground water contaminant fate/transport and distribution system models provided monthly estimated contaminant levels at residences. For PCE and TCE, the exposed group was divided into four levels: < median value, ≥ median value, ≥75th percentile, and ≥90th percentile. For benzene, the exposed group was categorized as <1 part per billion (ppb) versus ≥1 ppb because of sparse data. Magnitude of effect estimates and exposure response relationships were used to assess associations. Confidence intervals (CIs) indicated precision of estimates. RESULTS: For the highest TCE exposure category during the entire pregnancy, odds ratios (ORs) were 1.5 (95% CI: 1.2, 1.9) and 1.3 (95% CI: 0.8, 2.2) for SGA and TLBW, respectively, and reduced MBW ß = -78.3 g (95% CI: -115.0, -41.7). The OR =1.3 (95% CI: 1.0, 1.6) for preterm birth and the highest PCE exposure category during the entire pregnancy. Monotonic exposure-response relationships were observed for benzene exposure during the entire pregnancy and TLBW (highest category OR =1.5, 85% CI: 0.9, 2.3). Although a monotonic association between benzene and adjusted MBW difference was also observed (highest category ß = -36.2 g, 95% CI: -72.3, -0.1), the association disappeared when TCE was also added to the model. We found no evidence suggesting any other associations between outcomes and exposures. CONCLUSION: Findings suggested associations between in utero exposures to TCE and SGA, TLBW and reduced MBW; benzene and TLBW; and PCE and preterm birth.

Evaluation of mortality among marines and navy personnel exposed to contaminated drinking water at USMC base Camp Lejeune: a retrospective cohort study.

BACKGROUND: Two drinking water systems at U.S. Marine Corps Base Camp Lejeune, North Carolina were contaminated with solvents during 1950s-1985. METHODS: We conducted a retrospective cohort mortality study of Marine and Naval personnel who began service during 1975-1985 and were stationed at Camp Lejeune or Camp Pendleton, California during this period. Camp Pendleton's drinking water was uncontaminated. Mortality follow-up was 1979-2008. Standardized Mortality Ratios were calculated using U.S. mortality rates as reference. We used survival analysis to compare mortality rates between Camp Lejeune (N = 154,932) and Camp Pendleton (N = 154,969) cohorts and assess effects of cumulative exposures to contaminants within the Camp Lejeune cohort. Models estimated monthly contaminant levels at residences. Confidence intervals (CIs) indicated precision of effect estimates. RESULTS: There were 8,964 and 9,365 deaths respectively, in the Camp Lejeune and Camp Pendleton cohorts. Compared to Camp Pendleton, Camp Lejeune had elevated mortality hazard ratios (HRs) for all cancers (HR = 1.10, 95% CI: 1.00, 1.20), kidney cancer (HR = 1.35, 95% CI: 0.84, 2.16), liver cancer (HR = 1.42, 95% CI: 0.92, 2.20), esophageal cancer (HR = 1.43 95% CI: 0.85, 2.38), cervical cancer (HR = 1.33, 95% CI: 0.24, 7.32), Hodgkin lymphoma (HR = 1.47, 95% CI: 0.71, 3.06), and multiple myeloma (HR = 1.68, 95% CI: 0.76, 3.72). Within the Camp Lejeune cohort, monotonic categorical cumulative exposure trends were observed for kidney cancer and total contaminants (HR, high cumulative exposure = 1.54, 95% CI: 0.63, 3.75; log10 ß = 0.06, 95% CI: -0.05, 0.17), Hodgkin lymphoma and trichloroethylene (HR, high cumulative exposure = 1.97, 95% CI: 0.55, 7.03; ß = 0.00005, 95% CI: -0.00003, 0.00013) and benzene (HR, high cumulative exposure = 1.94, 95% CI: 0.54, 6.95; ß = 0.00203, 95% CI: -0.00339, 0.00745). Amyotrophic Lateral Sclerosis (ALS) had HR = 2.21 (95% CI: 0.71, 6.86) at high cumulative vinyl chloride exposure but a non-monotonic exposure-response relationship (ß = 0.0011, 95% CI: 0.0002, 0.0020). CONCLUSION: The study found elevated HRs at Camp Lejeune for several causes of death including cancers of the kidney, liver, esophagus, cervix, multiple myeloma, Hodgkin lymphoma and ALS. CIs were wide for most HRs. Because <6% of the cohort had died, long-term follow-up would be necessary to comprehensively assess effects of drinking water exposures at the base.

Mortality study of civilian employees exposed to contaminated drinking water at USMC Base Camp Lejeune: a retrospective cohort study.

BACKGROUND: Two drinking water systems at U.S. Marine Corps Base Camp Lejeune, North Carolina were contaminated with solvents during 1950s-1985. METHODS: We conducted a retrospective cohort mortality study of 4,647 civilian, full-time workers employed at Camp Lejeune during 1973-1985 and potentially exposed to contaminated drinking water. We selected a comparison cohort of 4,690 Camp Pendleton workers employed during 1973-1985 and unexposed to contaminated drinking water. Mortality follow-up period was 1979-2008. Cause-specific standardized mortality ratios utilized U.S. age-, sex-, race-, and calendar period-specific mortality rates as reference. We used survival analysis to compare mortality rates between Camp Lejeune and Camp Pendleton workers and assess the effects of estimated cumulative contaminant exposures within the Camp Lejeune cohort. Ground water contaminant fate/transport and distribution system models provided monthly estimated contaminant levels in drinking water serving workplaces at Camp Lejeune. The confidence interval (CI) indicated precision of effect estimates. RESULTS: Compared to Camp Pendleton, Camp Lejeune workers had mortality hazard ratios (HRs) >1.50 for kidney cancer (HR = 1.92, 95% CI: 0.58, 6.34), leukemias (HR = 1.59, 95% CI: 0.66, 3.84), multiple myeloma (HR = 1.84, 95% CI: 0.45, 7.58), rectal cancer (HR = 1.65, 95% CI: 0.36, 7.44), oral cavity cancers (HR = 1.93, 95% CI: 0.34, 10.81), and Parkinson's disease (HR = 3.13, 95% CI: 0.76, 12.81). Within the Camp Lejeune cohort, monotonic exposure-response relationships were observed for leukemia and vinyl chloride and PCE, with mortality HRs at the high exposure category of 1.72 (95% CI: 0.33, 8.83) and 1.82 (95% CI: 0.36, 9.32), respectively. Cumulative exposures were above the median for most deaths from cancers of the kidney, esophagus, rectum, prostate, and Parkinson's disease, but small numbers precluded evaluation of exposure-response relationships. CONCLUSION: The study found elevated HRs in the Camp Lejeune cohort for several causes of death including cancers of the kidney, rectum, oral cavity, leukemias, multiple myeloma, and Parkinson's disease. Only 14% of the Camp Lejeune cohort died by end of follow-up, producing small numbers of cause-specific deaths and wide CIs. Additional follow-up would be necessary to comprehensively assess drinking water exposure effects at the base.

Evaluation of exposure to contaminated drinking water and specific birth defects and childhood cancers at Marine Corps Base Camp Lejeune, North Carolina: a case-control study.

BACKGROUND: Drinking water supplies at Marine Corps Base Camp Lejeune were contaminated with trichloroethylene, tetrachloroethylene, benzene, vinyl chloride and trans-1,2-dichloroethylene during 1968 through 1985. METHODS: We conducted a case control study to determine if children born during 1968-1985 to mothers with residential exposure to contaminated drinking water at Camp Lejeune during pregnancy were more likely to have childhood hematopoietic cancers, neural tube defects (NTDs), or oral clefts. For cancers, exposures during the first year of life were also evaluated. Cases and controls were identified through a survey of parents residing on base during pregnancy and confirmed by medical records. Controls were randomly sampled from surveyed participants who had a live birth without a major birth defect or childhood cancer. Groundwater contaminant fate and transport and distribution system models provided estimates of monthly levels of drinking water contaminants at mothers' residences. Magnitude of odds ratios (ORs) was used to assess associations. Confidence intervals (CIs) were used to indicate precision of ORs. We evaluated parental characteristics and pregnancy history to assess potential confounding. RESULTS: Confounding was negligible so unadjusted results were presented. For NTDs and average 1st trimester exposures, ORs for any benzene exposure and for trichloroethylene above 5 parts per billion were 4.1 (95% CI: 1.4-12.0) and 2.4 (95% CI: 0.6-9.6), respectively. For trichloroethylene, a monotonic exposure response relationship was observed. For childhood cancers and average 1st trimester exposures, ORs for any tetrachloroethylene exposure and any vinyl chloride exposure were 1.6 (95% CI: 0.5-4.8), and 1.6 (95% CI: 0.5-4.7), respectively. The study found no evidence suggesting any other associations between outcomes and exposures. CONCLUSION: Although CIs were wide, ORs suggested associations between drinking water contaminants and NTDs. ORs suggested weaker associations with childhood hematopoietic cancers.

Causes of death among United States decedents with ALS: An eye toward delaying mortality.

OBJECTIVE: To report multiple cause of death (MCOD) occurrence among patients in the United States with amyotrophic lateral sclerosis (ALS). METHODS: Using death certificate data for all ALS deaths from 50 U.S. states and the District of Columbia, 2011-2014, we tabulated MCOD, used association rules mining (ARM) to determine if MCOD occurred together, and calculated standardized mortality odds ratios (SMOR) for select causes, comparing ALS with other U.S. decedents. RESULTS: Among 24,328 death certificates, there were 25,704 MCOD, excluding ALS. ALS was listed as the sole cause of death in n = 11,263 (46%). The most frequent causes of death co-occurring with ALS were respiratory failure (n = 6503; 25.3%), cardiovascular disease (n = 6077; 12.6%), pneumonia (n = 1345; 5.2%), and pneumonitis (n = 856; 3.3%). The SMORs among ALS decedents compared with non-ALS decedents for falls and accidents were 3.4 (95% CI 2.6, 4.3) and 3.0 (95% CI 2.2, 4.2), respectively. From ARM analysis, falls and accidents were both associated with injuries. The most common causes identified were weakly to very strongly associated with being an ALS decedent compared with other U.S. deaths, with SMOR point estimates ranging from 1.3 to 51.1. INTERPRETATION: This study provides information about the natural history of ALS. With knowledge that some causes of death may be preventable, healthcare providers may be able to optimize patient care and possibly postpone mortality and reduce morbidity. Moreover, this study located gaps in data; medical certifiers completing death certificates for ALS decedents should ensure all MCOD data are recorded.

Incidence of amyotrophic lateral sclerosis in the United States, 2014-2016.

Objective: To estimate the incidence of amyotrophic lateral sclerosis (ALS) in the United States for calendar years 2014-2016 using data from the National ALS Registry (Registry). The Registry collects data on ALS patients in the United States to better describe the epidemiology of ALS, examine risk factors such as environmental and occupational exposures, and characterize the demographics of those living with the disease. Methods: To identify adult incident cases of ALS, the Registry compiles data from three national administrative databases (maintained by the Centers for Medicare and Medicaid Services, the Veterans Health Administration, and the Veterans Benefits Administration). For cases that are not included in these databases, the Registry includes data collected from patients who voluntarily enroll via a secure web portal. Results: The Registry identified 5695 ALS cases in 2014; 6045 cases in 2015; and 4861 cases in 2016 for age-adjusted incidence rates of 1.7 (2014), 1.5 (2015), and 1.5 (2016) per 100,000 U.S. population, respectively. ALS was more common among whites, males, and persons aged 60-79 years. Conclusions: This is the first time administrative and self-reported databases have been used to describe the incidence of ALS for the United States resulting in a better estimate of disease demographics.

Prevalence of amyotrophic lateral sclerosis (ALS), United States, 2016.

Objective: To estimate the prevalence of amyotrophic lateral sclerosis (ALS) in the United States for 2016 using data from the National ALS Registry (Registry). Established in 2009, the Registry collects data on ALS patients in the U.S. to better describe the epidemiology of ALS, examine risk factors such as environmental and occupational exposures, and characterize the demographics of those living with the disease. Methods: To identify adult prevalent cases of ALS, the Registry compiles data from three national administrative databases (maintained by the Centers for Medicare and Medicaid Services, the Veterans Health Administration, and the Veterans Benefits Administration). To ascertain cases not necessarily included in these databases and to better understand risk-factors associated with ALS and disease progression, the Registry also includes data collected from patients who voluntarily enroll via a web portal to complete online surveys. Results: In 2016, the Registry conservatively identified 16,424 adult persons who met the Registry definition of ALS for an age-adjusted prevalence rate of 5.2 per 100,000 U.S. population. The pattern of patient characteristics (e.g., age, sex, and race/ethnicity) has not changed from previous Registry reports. Overall, ALS was more common among whites, males, and persons aged 60-69 years. The age groups with the lowest number of ALS cases were persons aged 18-39 years. Males had a higher prevalence rate of ALS than females overall and across all data sources. Conclusions: Data collected by the National ALS Registry are being used to better describe the epidemiology and demographics of ALS in the U.S.

Select mortality and cancer incidence among residents in various U.S. communities that received asbestos-contaminated vermiculite ore from Libby, Montana.

In response to the significantly elevated asbestosis mortality rates found in Libby, Montana, in 2000, this analysis evaluated whether other communities throughout the United States that received asbestos-contaminated vermiculite ore from Libby experienced similar excess rates of asbestos-related diseases. Standardized mortality ratios were calculated using state death certificates, and standardized incidence ratios were calculated using cancer registry records for populations living near facilities that processed or received Libby vermiculite. This analysis focused primarily on diseases that are directly associated with asbestos exposure (e.g., asbestosis; cancer of the peritoneum, retroperitoneum, and pleura, including mesothelioma; and mesothelioma). Lung cancer and cancers of the digestive system, also associated with asbestos exposure, were not included in the analysis because they have additional risk factors for which exposure information was not available. Data from 70 unique sites in 23 states were evaluated. No statistically significant excesses of asbestosis mortality similar to those in Libby were noted; however, 11 sites (plus a state with 6 pooled sites that were counted as 1 site) had excess rates of mesothelioma and cancer of the peritoneum, retroperitoneum, and pleura. Further investigation should be conducted at these sites with excess rates of mesothelioma and cancer of the peritoneum, retroperitoneum, and pleura by participating state health departments to determine whether exposure to Libby vermiculite might have been a contributing factor.

Wilms' tumor and exposures to residential and occupational hazardous chemicals.

This case-control study examines the association between residential and occupational exposures to hazardous chemicals and the risk of Wilms' tumor. The study included 303 cases recruited from six state cancer registries, who were diagnosed between January 1, 1992 and December 31, 1995. A total of 575 controls selected through random digit dialing were frequency matched to the cases. A standard questionnaire was administered to participants during a telephone interview. Parental residential addresses and locations of US Environmental Protection Agency National Priority List (NPL) sites were geocoded and analyzed, along with occupational exposure information. There were no cases of Wilms' tumor found in individuals living within one-half mile distance of a hazardous waste site. However, elevated odds ratios were found for using hairdressing chemicals, motor oil, paint, paint stripper, and pesticides during the pregnancy term and during the 2-year period prior to birth. The findings do not support the hypothesis that Wilms' tumor is associated with residing near an NPL site.

Lead exposure and birth outcomes in five communities in Shoshone County, Idaho.

INTRODUCTION: This study examined birth outcomes in five towns in Shoshone County, Idaho, where residents were exposed to high levels of lead in air emissions during a 6-month period after a fire had damaged the main baghouse (pollution-control device) of a local lead smelter plant in September 1973. METHODS: We studied birth certificate data of 169,878 live singleton infants born to mothers who resided in Idaho at the time of delivery. The outcomes evaluated were preterm infants, small-for-gestational-age (SGA) infants, low birthweight among term infants (TLBW), and mean birthweight among term infants (TMBW). The study compared births in the five towns in Shoshone County (exposed group) to births in the rest of Idaho during three exposure periods: "pre-fire," January 1, 1970-August 31, 1973; "high exposure," September 1, 1973-December 31, 1974; and "post-fire," January 1, 1975-December 31, 1981. RESULTS: During the high-exposure period, the exposed group had an increased prevalence of TLBW (OR=2.4; 90% CI: 1.6-3.6) and SGA (OR=1.9; 90% CI: 1.3-2.8) compared with the rest of Idaho. During the pre- and post-fire periods, the ORs for TLBW were 0.8 and 1.3, respectively, and for SGA, 1.0, and 1.3, respectively. During the high-exposure period, TMBW for the exposed group was 71 g lower than in the comparison group. The TMBW in the exposed group was 8 g lower in the pre-fire period and 26 g lower in the post-fire period than in the comparison group. The study found no increased risk for preterm birth in the exposed group. CONCLUSIONS: Maternal exposures to airborne lead emissions appeared to be associated with increased risks for SGA, TLBW, and reduced TMBW.

Reconstructing Historical VOC Concentrations in Drinking Water for Epidemiological Studies at a U.S. Military Base: Summary of Results.

A U.S. government health agency conducted epidemiological studies to evaluate whether exposures to drinking water contaminated with volatile organic compounds (VOC) at U.S. Marine Corps Base Camp Lejeune, North Carolina, were associated with increased health risks to children and adults. These health studies required knowledge of contaminant concentrations in drinking water-at monthly intervals-delivered to family housing, barracks, and other facilities within the study area. Because concentration data were limited or unavailable during much of the period of contamination (1950s-1985), the historical reconstruction process was used to quantify estimates of monthly mean contaminant-specific concentrations. This paper integrates many efforts, reports, and papers into a synthesis of the overall approach to, and results from, a drinking-water historical reconstruction study. Results show that at the Tarawa Terrace water treatment plant (WTP) reconstructed (simulated) tetrachloroethylene (PCE) concentrations reached a maximum monthly average value of 183 micrograms per liter (µg/L) compared to a one-time maximum measured value of 215 µg/L and exceeded the U.S. Environmental Protection Agency's current maximum contaminant level (MCL) of 5 µg/L during the period November 1957-February 1987. At the Hadnot Point WTP, reconstructed trichloroethylene (TCE) concentrations reached a maximum monthly average value of 783 µg/L compared to a one-time maximum measured value of 1400 µg/L during the period August 1953-December 1984. The Hadnot Point WTP also provided contaminated drinking water to the Holcomb Boulevard housing area continuously prior to June 1972, when the Holcomb Boulevard WTP came on line (maximum reconstructed TCE concentration of 32 µg/L) and intermittently during the period June 1972-February 1985 (maximum reconstructed TCE concentration of 66 µg/L). Applying the historical reconstruction process to quantify contaminant-specific monthly drinking-water concentrations is advantageous for epidemiological studies when compared to using the classical exposed versus unexposed approach.

Drinking water contaminants and adverse pregnancy outcomes: a review.

Concern for exposures to drinking water contaminants and their effects on adverse birth outcomes has prompted several studies evaluating chlorination disinfection by-products and chlorinated solvents. Some of these contaminants are found to be teratogenic in animal studies. This review evaluates 14 studies on chlorination disinfection by-products such as trihalomethanes (THMs) and five studies on chlorinated solvents such as trichloroethylene (TCE). The adverse birth outcomes discussed in this review include small for gestational age (SGA), low birth weight, preterm birth, birth defects, spontaneous abortions, and fetal deaths. Because of heterogeneities across the studies in the characterization of birth outcomes, the assessment and categorization of exposures, and the levels and mixtures of contaminants, a qualitative review was conducted. Generally, the chief bias in these studies was exposure misclassification that most likely underestimated the risk, as well as distorted exposure-response relationships. The general lack of confounding bias by risk factors resulted from these factors not being associated with drinking water exposures. The studies of THMs and adverse birth outcomes provide moderate evidence for associations with SGA, neural tube defects (NTDs), and spontaneous abortions. Because fewer studies have been conducted for the chlorinated solvents than for THMs, the evidence for associations is less clear. Nevertheless, the findings of excess NTDs, oral clefts, cardiac defects, and choanal atresia in studies that evaluated TCE-contaminated drinking water deserve follow-up.

Long-term neurobehavioral health effects of methyl parathion exposure in children in Mississippi and Ohio.

Methyl parathion (MP), an organophosphate pesticide licensed only for agricultural uses, was sprayed illegally for pest control in Mississippi and Ohio residences. To evaluate the association between MP exposure and neurobehavioral development, we assessed children 6 years or younger at the time of the spraying and local comparison groups of unexposed children using the Pediatric Environmental Neurobehavioral Test Battery (PENTB). The PENTB is composed of informant-based procedures (parent interview and questionnaires) and performance-based procedures (neurobehavioral tests for children 4 years or older) that evaluate cognitive, motor, sensory, and affect domains essential to neurobehavioral assessment. Children were classified as exposed or unexposed on the basis of urinary para-nitrophenol levels and environmental wipe samples for MP. Exposed children had more difficulties with tasks involving short-term memory and attention. Additionally, parents of exposed children reported that their children had more behavioral and motor skill problems than did parents of unexposed children. However, these effects were not consistently seen at both sites. There were no differences between exposed and unexposed children in tests for general intelligence, the integration of visual and motor skills, and multistep processing. Our findings suggest that MP might be associated with subtle changes to short-term memory and attention and contribute to problems with motor skills and some behaviors, but the results of the study are not conclusive.

Elevated birth defects in racial or ethnic minority children of women living near hazardous waste sites.

This case-control study evaluated the relationship between birth defects in racial or ethnic minority children born during 1983-1988 and the potential exposure of their mothers to contaminants at hazardous waste sites in California. Four categories of race or ethnicity were used: black/African American, Hispanic/Latino, American Indian/Alaska Native, and Asian/Pacific Islander. Case subjects were 13,938 minority infants with major structural birth defects (identified by the California Birth Defects Monitoring Program) whose mothers resided in selected counties at the time of delivery. The control group was composed of 14,463 minority infants without birth defects who were randomly selected from the same birth cohort as the case subjects. The potential for exposure was determined by whether the mother resided at the time of delivery in the same census tract as a hazardous waste site that was on the U.S. Environmental Protection Agency's National Priorities List (NPL). Racial/ethnic minority infants whose mothers had been potentially exposed to hazardous waste were at slightly increased risk for birth defects (odds ratio [OR] = 1.12, 95% confidence interval [CI] = 0.98-1.27) than were racial/ethnic minority infants whose mothers had not been potentially exposed. The greatest association was between potential exposure and neural tube defects (OR = 1.54, 95% CI = 0.93-2.55), particularly anencephaly (OR = 1.85, 95% CI = 0.91-3.75). The strongest association between birth defects and potential exposure was among American Indians/Alaska Natives (OR = 1.19, 95% CI = 0.62-2.27). Despite the limitations of this study, the consistency of these findings with previous studies suggests an association between environmental risk factors and birth defects. This is particularly relevant to minority populations. We recommend further investigation of birth defects among minority communities, particularly among American Indians/Alaska Natives. Special attention should also be paid to those defects and contaminants that consistently are associated with exposure to hazardous waste.

Population exposures to I-131 releases from Hanford Nuclear Reservation and preterm birth, infant mortality, and fetal deaths.

Communities surrounding the Hanford Nuclear Reservation in southeastern Washington were exposed to radionuclides, particularly iodine-131, released during the period 1945 to 1951. This study evaluated whether estimated iodine-131 exposures were risk factors for infant mortality, fetal death, and preterm birth in the years of highest releases, 1945 and 1946. Data on births, fetal deaths, and infant deaths, during the period 1940 to 1950, were abstracted from vital records for an eight county area surrounding the Hanford facility. The analysis included 56,320 births, 1,656 infant deaths, and 806 fetal deaths. The Hanford Environmental Dose Reconstruction project provided iodine-131 dose estimates for the 1,102 grid areas in the study area. The grid areas were collapsed into 4 exposure groups using estimated exposure to iodine-131 during 1945. Each birth and death record was assigned to one of the four grid groups based on mother's residence at the time of birth. Comparisons of preterm birth, infant death, and fetal death rates were made among the grid groupings for the primary exposure period (1945 to 1946) and for other years of the study period (i.e., 1940 to 1944 and 1947 to 1950). In the grid group with the highest estimated iodine-131 exposures, the mother's residence during the latter part of pregnancy was associated with preterm birth (OR = 1.74, 95% CI = 1.09-2.72). An association with infant mortality (OR = 1.26, 95% CI = 0.79-1.97) was suggested. No association was found for fetal deaths. This study found that iodine-131 exposure was associated with increased risk of preterm birth. This finding is biologically plausible because other studies have found that: (1) iodine-131 exposure can cause hypothyroidism, and (2) overt or subclinical hypothyroidism during pregnancy can increase a mother's risk of a preterm delivery.

Association between cumulative fiber exposure and respiratory outcomes among Libby vermiculite workers.

OBJECTIVE: To examine the association between cumulative fiber exposure and health outcomes in workers (n = 336) with Libby amphibole exposure. METHODS: Exposure-response relationships were explored by the use of logistic regression, with cumulative fiber exposure modeled in categories and as a continuous variable. RESULTS: The use of spline functions with lifetime cumulative fiber exposure as a continuous variable showed that the odds of localized pleural thickening were significantly elevated at less than 1 f/cc-y. Odds of parenchymal abnormalities, restrictive spirometry, and chronic bronchitis were also significantly elevated at 108, 166, and 24 f/cc-y, respectively. CONCLUSIONS: The odds of several pulmonary health outcomes are correlated with cumulative exposure to Libby amphibole. That relatively low-lifetime cumulative exposures are associated with localized pleural thickening has implications for the non-cancer-risk assessment for Libby amphibole.

Vermiculite worker mortality: estimated effects of occupational exposure to Libby amphibole.

OBJECTIVE: To examine the relationship between cumulative fiber exposure (CFE) and mortality in a retrospective cohort study of vermiculite workers exposed to Libby amphibole (n = 1862). METHODS: Extended Cox regression was used to estimate the hazards associated with CFE as a time-dependent covariate of multiple-cause mortality. RESULTS: The Cox models for mesothelioma, asbestosis, lung cancer, and non-malignant respiratory disease were significant with rate ratios that increased monotonically with CFE. The model for deaths due to cardiovascular disease was also significant (rate ratio for CFE > or =44.0 f/cc-y vs <1.4 f/cc-y was 1.5; 95% confidence interval = 1.1 to 2.0). CONCLUSIONS: By using a within-cohort comparison, the results demonstrate a clear exposure-response relationship between CFE and mortality from asbestos-related causes. The finding of an association between CFE and cardiovascular mortality suggests persons exposed to Libby amphibole should be monitored for this outcome.