Reproductive outcomes among former Love Canal residents, Niagara Falls, New York.

Love Canal, located in Niagara Falls, NY, and among the earliest and most significant hazardous waste sites in the United States, first came to public attention in 1978. In this study, researchers evaluated 1,799 live births from 1960 through 1996 to 980 women who formerly lived in the Love Canal Emergency Declaration Area and were of reproductive age sometime during that time period. Using Upstate New York and Niagara County as external comparison populations, standardized incidence ratios with 95% confidence intervals were calculated for low birth weight, preterm birth, small for gestational age, and congenital malformations, and unadjusted proportions of male to female births were calculated. Internal comparisons among the infants were also performed according to several measures of potential exposure using generalized estimating equations. The results indicated a statistically significant elevated risk of preterm birth among children born on the Love Canal prior to the time of evacuation and relocation of residents from the Emergency Declaration Area, using Upstate New York as the standard population (standardized incidence ratio=1.40; 95% confidence interval: 1.01, 1.90). Additionally, the ratio of male to female births was lower for children conceived in the Emergency Declaration Area (sex ratio=0.94 versus sex ratio=1.05 in the standard population) and the frequency of congenital malformations was greater than expected among Love Canal boys born from 1983 to 1996 (standardized incidence ratio=1.50 when compared to Upstate New York), although in both cases the 95% confidence interval included the null value. Finally, increased risk for low birth weight infants among mothers who lived closest to the Canal as children was found (odds ratio=4.68; 95% confidence interval: 1.24, 17.66), but this estimate was limited due to small numbers (n=4). The study adds to the knowledge of the possible reproductive effects from exposure to chemicals arising from hazardous waste; however, given the small number of some events, the qualitative nature of the exposure assessment, and possibility of spurious associations due to multiple comparisons, the findings should be interpreted cautiously.

Concentrations of selected organochlorines and chlorobenzenes in the serum of former Love Canal residents, Niagara Falls, New York.

BACKGROUND: Love Canal, in Niagara Falls, NY is among the earliest and most significant hazardous waste sites in the USA, but no study has ever measured chemical body burdens in nearby residents to document that human exposure occurred. This study measured concentrations of selected organochlorines and chlorinated benzenes in archived serum samples collected from former Love Canal residents. METHODS: We analyzed serum samples collected from 373 former residents in 1978-1979 for compounds disposed of at Love Canal, and we compared their concentrations according to surrogate indicators of exposure such as residential proximity, adjusting for potential confounders. RESULTS: Three compounds were detectable in the serum of most participants: 1,2,4-trichlorobenzene (1,2,4-TCB), beta-hexachlorocyclohexane (beta-HCH) and 1,2-dichlorobenzene (1,2-DCB). Concentrations of 1,2,4-TCB and 1,2-DCB were 2-14 times greater among persons who at the time their blood was collected lived closest to the Canal compared to those living further away. We found no consistent trends for beta-HCH with respect to any exposure definition. CONCLUSIONS: These results provide evidence that residential proximity to Love Canal contributed to the body burden of certain contaminants, and helps validate the use of surrogate exposure measures in health effect studies. Further surveillance of the Love Canal cohort is warranted.

Cancer incidence among former Love Canal residents.

BACKGROUND: The Love Canal was a rectangular 16-acre, 10-ft-deep chemical waste landfill situated in a residential neighborhood in Niagara Falls, New York. This seriously contaminated site came to public attention in 1978. Only one prior study examined cancer incidence in former residents of the Love Canal neighborhood (LC). OBJECTIVE: In this study we aimed to describe cancer incidence in former LC residents from 1979 to 1996 and to investigate whether it differs from that of New York State (NYS) and Niagara County (NC). METHODS: From 1978 to 1982, we interviewed 6,181 former residents, and 5,052 were eligible to be included in this study. In 1996, we identified 304 cancer diagnoses in this cohort using the NYS Cancer Registry. We compared LC cancer incidence with that of NYS and NC using standardized incidence ratios (SIRs), and we compared risks within the LC group by potential exposure to the landfill using survival analysis. RESULTS: SIRs were elevated for cancers of the bladder [SIR(NYS) = 1.44; 95% confidence interval (CI), 0.91-2.16] and kidney (SIR(NYS) = 1.48; 95% CI, 0.76-2.58). Although CIs included 1.00, other studies have linked these cancers to chemicals similar to those found at Love Canal. We also found higher rates of bladder cancer among residents exposed as children, based on two cases. CONCLUSIONS: In explaining these excess risks, the role of exposure to the landfill is unclear given such limitations as a relatively small and incomplete study cohort, imprecise exposure measurements, and the exclusion of cancers diagnosed before 1979. Given the relatively young age of the cohort, further surveillance is warranted.

Mortality among former Love Canal residents.

BACKGROUND: The Love Canal is a rectangular 16-acre, 10-ft deep chemical waste landfill situated in a residential neighborhood in Niagara Falls, New York. This seriously contaminated site first came to public attention in 1978. No studies have examined mortality in the former residents of the Love Canal neighborhood (LC). OBJECTIVE: The aim of this study was to describe the mortality experience of the former LC residents from the years 1979-1996. METHODS: From 1978 to 1982, 6,181 former LC residents were interviewed. In 1996, 725 deaths from 1979-1996 were identified in this cohort, using state and national registries. We compared mortality rates with those of New York State (NYS) and Niagara County. Survival analysis examined risks by potential exposure to the landfill. RESULTS: We were unable to demonstrate differences in all-cause mortality for either comparison population for 1979 1996. Relative to NYS, the standardized mortality ratio (SMR) was elevated [SMR = 1.39; 95% confidence interval (CI), 1.16-1.66] for death from acute myocardial infarction (AMI), but not relative to Niagara County. Death from external causes of injury was also elevated relative to both NYS and Niagara County, especially among women (SMR = 1.95; 95% CI, 1.25 2.90). CONCLUSIONS: The role of exposure to the landfill in explaining these excess risks is not clear given limitations such as multiple comparisons, a qualitative exposure assessment, an incomplete cohort, and no data on deaths prior to 1978. Lack of elevation for AMI when compared with Niagara County but not NYS suggests possible regional differences. However, direct cardiotoxic or neurotoxic effects from landfill chemicals or indirect effects mediated by psychological stress cannot be ruled out. Revisiting the cohort in the future could reveal patterns that are not yet apparent.

Maternal caffeine consumption and risk of cardiovascular malformations.

BACKGROUND: The physiologic effects and common use of caffeine during pregnancy call for examination of maternal caffeine consumption and risk of birth defects. Epidemiologic studies have yielded mixed results, but such studies have grouped etiologically different defects and have not evaluated effect modification. METHODS: The large sample size and precise case classification of the National Birth Defects Prevention Study allowed us to examine caffeine consumption and specific cardiovascular malformation (CVM) case groups. We studied consumption of caffeinated coffee, tea, soda, and chocolate to estimate total caffeine intake and separately examined exposure to each caffeinated beverage. Smoking, alcohol, vasoactive medications, folic acid supplement use, and infant gender were evaluated for effect modification. Maternal interview reports for 4,196 CVM case infants overall and 3,957 control infants were analyzed. RESULTS: We did not identify any significant positive associations between maternal caffeine consumption and CVMs. For tetralogy of Fallot, nonsignificant elevations in risk were observed for moderate (but not high) caffeine intake overall and among nonsmokers (ORs of 1.3 to 1.5). Risk estimates for both smoking and consuming caffeine were less than the sum of the excess risks for each exposure. We observed an inverse trend between coffee intake and risk of atrial septal defect; however, this single significant pattern of association might have been a chance finding. CONCLUSIONS: Our study found no evidence for an appreciable teratogenic effect of caffeine with regard to CVMs.

Problems in using birth certificate files in the capture-recapture model to estimate the completeness of case ascertainment in a population-based birth defects registry in New York State.

BACKGROUND: The limitations and underlying assumptions of the capture-recapture methods have hindered their application in epidemiological settings, especially in evaluating the completeness of birth defects registries. This study explored the possibility of using birth certificates as the secondary data source in a simple two-source capture-recapture model to estimate the completeness of case ascertainment of the Congenital Malformations Registry (CMR) for selected major birth defects. METHODS: The CMR and the birth certificates were used as the primary and secondary sources, respectively. Children who were born in 1996-2001 and had selected major birth defects were identified from the two sources. The accuracy of the diagnoses was examined by comparing the individual birth defect categories of the children from the two sources. RESULTS: Discrepancies in birth defect categories in the two data sources and false positives in the birth certificates were the major problems encountered in estimating the completeness of the CMR using the simple two-source capture-recapture method. The estimated completeness for selected major birth defects was only about 71%. Stratified analyses resulted in relatively high estimated completeness for oral clefts (90%) and Down syndrome (88%). CONCLUSIONS Although the birth certificate data was not a good source for estimating the completeness of case ascertainment of the CMR using capture-recapture methods, the analyses provided reasonable estimates for some conditions that were relatively easy to identify and diagnose at birth, such as oral clefts and Down syndrome.

Down syndrome: interaction between culture, demography, and biology in determining the prevalence of a genetic trait.

The incidence of Down syndrome (DS) at conception is highly dependent upon the maternal age distribution and age-specific pregnancy rates. Live-birth prevalence of DS reflects these factors and fetal deaths. Since the introduction of prenatal diagnosis in the early 1970s, the role of fetal deaths in the equation has increased. Between 1920 and the early 1980s, DS live-birth prevalence decreased in many populations due to declining fertility rates, particularly among older women. In the late-1970s the trend reversed, as the median age of populations and birth rates among older women steadily increased. This paper illustrates these interactions using data we have analyzed for New York State (NYS) and comparative data obtained from the literature. Between 1983 and 1997 DS live-birth prevalence in NYS remained stable at about 9.9 per 10,000 live births. The number of prenatal tests performed increased by 158%, and the number of DS fetuses detected prenatally more than quadrupled. Fertility rates of women aged 35-49 continued to increase. The proportion of DS cases born to these older mothers increased from 23% in 1985 to 43% in 1997. We estimated that without prenatal diagnosis, DS live-birth prevalence would have been 17.0 per 10,000 live births by 1995. Cultural factors influence demographic trends, birthing technologies, physician practices, and women's decision-making regarding prenatal screening and diagnosis for DS.