Environmental health collaboration: United States and Russia.

Developed nations share similar challenges to human health from commercial and agricultural chemicals that are released into the environment. Although Russia and the United States are historically distinct and unique, both countries are geographically large and economically dependent on emission-producing surface transportation. This paper describes U.S.-Russian collaborative activities that grew from a 1995 conference in Moscow that brought together environmental health investigators from both countries to discuss common concerns about the human health impact of environmental pollutants. Lead, pesticides, volatile organic compounds, and mercury were identified as contaminants of greatest concern. Collaborative studies were initiated that included collecting blood and hair samples and splitting samples for analyses in both countries, and introducing and sharing new portable blood and environmental sample analyses instruments. The findings demonstrated that hair analysis was not a good predictor of BLL and that Russian children in the first city sampled had a mean BLL of 7.7 microg/dl. Although higher than the U.S. mean, this level was below the 10.0 microg/dl CDC level of concern. This manuscript summarizes additional study results and describes their impacts on Russian policy. On-going collaborative environmental investigations are described.

Heat-related death and mental illness during the 1999 Cincinnati heat wave.

During a 1999 heat wave in Cincinnati, Ohio, the Hamilton County Coroner reported 18 heat-related deaths. The Centers for Disease Control and Prevention and the Cincinnati Department of Health conducted a case-control study using surrogate case information and first-person control information to identify risk factors for mortality during the heat wave. Surrogate data were supplemented by systematic death scene investigation reports and comprehensive toxicologic screens, important sources of data that are routinely collected by the Hamilton County Coroner's Office. The study included 17 case subjects and 34 controls from the decedents' neighborhood. Among 17 case subjects, 8 (47.1%) had mental illness (odds ratio [OR], 14.0; 95% confidence interval [CI], 1.8-633). There was a suggestion of an interaction between age and mental health. A working air-conditioner was the strongest protective factor (OR, 0.03; 95% CI, 0-0.2). Toxicologic screening indicated that case subjects with reported mental illness and a prescription for psychotropic drugs may not have been medication compliant. Three decedents lived in group homes for people with mental illness, indicating that opportunities for prevention may have been missed. Systematic death investigations, including toxicologic screening, provide valuable information about the circumstances of heat-related death, particularly the role of medication compliance as a risk factor. Prevention programs during heat waves should target people with mental illness, especially those who take psychotropic medication.

Exposure to persistent organochlorines among Alaska Native women.

OBJECTIVES: To report the levels of DDT, DDE, other chlorinated pesticides, and PCBs found in 131 Alaska Native women who had serum samples collected between 1980 and 1987 and to compare these levels to other published studies of DDE and PCB exposure among U.S. women. STUDY DESIGN: Review of data collected during a case-control study of the relationship between organochlorine chemicals and breast cancer. Data for case and control women were pooled in this analysis because case-control differences were found to be minimal and because serum samples pre-dated cancer diagnoses by 3 to 10 years. RESULTS: More than 99% of the women had detectable levels of p,p-DDE (mean 9.10 ng/mL or ppb). Mean total PCB level was 7.56 ppb. Levels of exposure varied by geographical location and ethnic identification, which maybe a reflection of dietary differences. Five of the organochlorines were detected in at least half of the study population. Results were recalculated using detection limits corresponding to other published studies of DDE and PCB levels in U.S. women. Alaska women had levels similar to those reported from New York women collected in the 1980s. We compared the PCB congener levels measured in Alaska Native women with levels reported in Arctic animals and found similar PCB congener profiles. The six most frequently detected contaminants in Alaska Natives were also detected in the marine mammal samples reported by Becker et al (5). CONCLUSIONS: Our study identified widespread Alaska Native exposure to organochlorines that originated outside of the Arctic, a finding also seen in other studies. Our results provide a reference baseline for exposure levels during the 1980s, but further research is necessary to assess temporal trends in exposure among Alaska Natives. Further, the need for national and international inter-laboratory standardization for testing for persistent organochlorines to facilitate comparisons between Alaska Natives and other American populations is clearly demonstrated.

Blood lead levels of primary school children in Dhaka, Bangladesh.

Dhaka, Bangladesh, has one of the highest air lead levels in the world. In February 2000, we evaluated children at five primary schools in Dhaka to determine blood lead (BPb) levels, sources of environmental exposure, and potential risk factors for lead poisoning. Selected schools represented a range of geographic and socioeconomic strata. A total of 779 students 4-12 years of age participated. The mean BPb level was 15.0 microg/dL (range 4.2-63.1 microg/dL). Most students (87.4%) had BPb levels above the Centers for Disease Control and Prevention's level of concern (10 microg/dL). Elevated BPb levels correlated with soil eating [odds ratio (OR) = 3.31; 95% confidence interval (CI), 1.30-8.39], low parental education (OR = 2.72; 95% CI, 1.97-3.75), living close to major roads (OR = 2.30; 95% CI, 1.23-4.29), and increasing age (OR = 1.11; 95% CI, 1.06-1.16). BPb levels measured were similar to those in other countries that use leaded gasoline. No other potential sources of lead exposure were consistently identified. Combustion of leaded gasoline is the main source of lead exposure in Dhaka, resulting in ubiquitous contamination of the environment. The increase in BPb levels with age, a finding contrary to observations in the United States and Australia, may be related to increased outdoor activities. The Bangladeshi government recently announced a plan to eliminate leaded gasoline. Baseline BPb surveys are critical to develop and evaluate intervention policies. Strategies to reduce BPb levels need to address variations in socioeconomic status, construction type and location of housing, and levels of hygiene.

Hair and blood as substrates for screening children for lead poisoning.

In Russia, hair, rather than blood, is usually used as a substrate for screening children for lead poisoning. We attempted to gauge the accuracy of this method by comparing these two methods. The evaluation was done in Saratov, Russia. We collected hair and blood samples from 189 children who attended 11 kindergartens. Their mean blood lead concentration was 9.8 microg/dl (range = 3.1-35.7 microg/dl), and their mean hair lead concentration was 7.2 microg/g (range = 1.0-7.2 microg/g [i.e., 1.0 being the lowest detectable limit]). Hair lead concentration as a screening method had 57% sensitivity and resulted in 18% of the children being classified as false-negatives. We conclude, therefore, that measuring hair lead concentration is not an adequate method with which to screen children for lead poisoning.

Water distribution system and diarrheal disease transmission: a case study in Uzbekistan.

Deteriorating water treatment facilities and distribution systems pose a significant public health threat, particularly in republics of the former Soviet Union. Interventions to decrease the disease burden associated with these water systems range from upgrading distribution networks to installing reverse osmosis technology. To provide insight into this decision process, we conducted a randomized intervention study to provide epidemiologic data for water policy decisions in Nukus, Uzbekistan, where drinking water quality is suboptimal. We interviewed residents of 240 households, 120 with and 120 without access to municipal piped water. Residents of 62 households without piped water were trained to chlorinate their drinking water at home in a narrow-necked water container with a spout. All study subjects (1583 individuals) were monitored biweekly for self-reported diarrheal illness over a period of 9.5 weeks. The home chlorination intervention group had the lowest diarrheal rate (28.8/1,000 subjects/month) despite lack of access to piped water in their homes. Compared with the two groups that did not receive the intervention this rate was one-sixth that of the group with no piped water (179.2/1,000 subjects/month) and one-third that of the households with piped water (75.5/1,000 subjects/month). More than 30% of the households with piped water lacked detectable levels of chlorine residues in their drinking water, despite two-stage chlorination of the source water, and were at increased risk of diarrhea. Forty-two percent of these municipal users reported that water pressure had been intermittent within the previous two days. The dramatic reduction in diarrheal rates in the home-chlorination intervention group indicates that a large proportion of diarrheal diseases in Nukus are water-borne. The home-chlorination group had less diarrhea than the group with piped water, implicating the distribution system as a source of disease transmission. Taken together, these epidemiologic data would support the hypothesis that diarrhea in the piped water group could be attributed to cross-contamination between the municipal water supply and sewer, due to leaky pipes and lack of water pressure. Relatively inexpensive steps, including chlorination, maintaining water pressure, and properly maintaining the distribution system, rather than reverse osmosis technology, should reduce diarrheal rates.

Reproductive toxins and alligator abnormalities at Lake Apopka, Florida.

The alligator population at Lake Apopka in central Florida declined dramatically between 1980 and 1987. Endocrine-disrupting chemicals and specifically DDT metabolites have been implicated in the alligators' reproductive failure. The DDT metabolite hypothesis is based largely on the observation of elevated concentrations of p,p-DDE and p,p-DDD in alligator eggs obtained from Lake Apopka in 1984 and 1985. In the following commentary, we draw attention to two nematocides that are established reproductive toxins in humans, dibromochloropropane (DBCP) and ethylene dibromide (EDB), which could also have played a role in the reproductive failure observed in alligators from Lake Apopka in the early 1980s.

Heat-related deaths during the July 1995 heat wave in Chicago.

BACKGROUND: During a record-setting heat wave in Chicago in July 1995, there were at least 700 excess deaths, most of which were classified as heat-related. We sought to determine who was at greatest risk for heat-related death. METHODS: We conducted a case-control study in Chicago to identify risk factors associated with heat-related death and death from cardiovascular causes from July 14 through July 17, 1995. Beginning on July 21, we interviewed 339 relatives, neighbors, or friends of those who died and 339 controls matched to the case subjects according to neighborhood and age. RESULTS: The risk of heat-related death was increased for people with known medical problems who were confined to bed (odds ratio as compared with those who were not confined to bed, 5.5) or who were unable to care for themselves (odds ratio, 4.1). Also at increased risk were those who did not leave home each day (odds ratio, 6.7), who lived alone (odds ratio, 2.3), or who lived on the top floor of a building (odds ratio, 4.7). Having social contacts such as group activities or friends in the area was protective. In a multivariate analysis, the strongest risk factors for heat-related death were being confined to bed (odds ratio, 8.2) and living alone (odds ratio, 2.3); the risk of death was reduced for people with working air conditioners (odds ratio, 0.3) and those with access to transportation (odds ratio, 0.3). Deaths classified as due to cardiovascular causes had risk factors similar to those for heat-related death. CONCLUSIONS: In this study of the 1995 Chicago heat wave, those at greatest risk of dying from the heat were people with medical illnesses who were socially isolated and did not have access to air conditioning. In future heat emergencies, interventions directed to such persons should reduce deaths related to the heat.

Occupation and lung cancer mortality among women: using occupation to target smoking cessation programs for women.

Lung cancer mortality rates are increasing for women, despite the fact that 90% of these deaths could be prevented by smoking cessation. Targeted workplace smoking cessation programs may increase the effectiveness of lung cancer prevention for women. This study uses proportionate mortality ratio analysis of occupationally coded death certificates, from 28 states between 1979 and 1990, to identify occupations in which women are at high risk of lung cancer mortality. The study found gender and racial variation in the results for broad occupational groups. Blue-collar occupations associated with potentially carcinogenic workplace exposures also had elevated proportionate mortality ratios, probably reflecting both occupational and tobacco exposure. For women, specific occupations such as managers and financial officers revealed significant elevations in lung cancer mortality. Cessation programs targeting women in these occupational groups may increase the effectiveness of lung cancer prevention.

Evaluating a fluorosis hazard after a volcanic eruption.

The August, 1991 eruption of Mt. Hudson (Chile) deposited ash across southern Argentina and contributed to the deaths of thousands of grazing sheep. Early ash analysis revealed high levels of fluoride, a potential ash constituent toxic to humans and animals. In order to evaluate fluorosis as the cause of sheep deaths and to examine the possibility that similar ash and airborne toxins could also have an effect on the human population, we conducted an investigation that included health provider interviews, hospital record review, physical examination of sheep, determination of sheep urine fluoride levels, and complete constituent analysis of ash samples collected at proscribed distances from the volcano. Ash deposited farthest from the volcano had highest fluoride levels; all fluoride measurements were normal after rainfall. There were no signs or symptoms of fluorosis observed in sheep or humans. Sheep deaths resulted from physical, rather than chemical properties of the ash.

Nutritional survey of an elderly Russian population. CARE International Working Group.

During March and April 1992, CARE International, with epidemiological support from the Centers for Disease Control and Prevention, conducted household surveys of pensioners 70 years of age or older in two Russian cities. The objectives of these studies were to assess survey feasibility, to report baseline nutritional data, and to determine if demographic identifiers on computerized government listings could be used to target nutritional aid toward the most needy among elderly people. Pensioners in each city were administered questionnaires regarding food consumption and financial and health status. We calculated scores for body mass index (BMI) and Nutritional Screening Initiative (NSI) Checklist (a tool for assessing the nutritional risk status of U.S. elderly). Median pension income was 410 roubles (about $4.00) per month. Forty-five percent of the participants had < or = 500 roubles in savings, 64% reported dental problems, and 60% responded that they had medical problems that interfered with eating. Although the Russian BMI distribution was similar to that of a comparison U.S. elderly population, the Russian NSI score totals were unfavorably elevated. The mean NSI score of 8.8 is more than twice the reported U.S. mean. We found no single demographic identifier to predict the elderly subjects considered at greatest risk, according to NSI scoring. Longitudinal follow-up of these pensioners will be used for continuing assessment of the impact of economic restructuring in Russia upon elderly citizens.

Occupation as a risk identifier for breast cancer.

OBJECTIVES: Breast cancer mortality may be reduced if the disease is detected early through targeted screening programs. Current screening guidelines are based solely on a woman's age. Because working populations are accessible for intervention, occupational identification may be a way of helping to define and locate risk groups and target prevention. METHODS: We used a database consisting of 2.9 million occupationally coded death certificates collected from 23 states between 1979 and 1987 to calculate age-adjusted, race-specific proportionate mortality ratios for breast cancer according to occupation. We performed case-control analyses on occupational groups and on stratifications within the teaching profession. RESULTS: We found a number of significant associations between occupation and frequency of breast cancer. For example, white female professional, managerial, and clerical workers all had high proportions of breast cancer death. High rates of breast cancer in teachers were found in both proportionate mortality ratio and case-control analyses. CONCLUSIONS: These findings may serve as in an aid in the effective targeting of work-site health promotion programs. They suggest that occupationally coded mortality data can be a useful adjunct in the difficult task of identifying groups at risk of preventable disease.

Discrepancy in mosaic findings between chorionic villi and amniocytes: a diagnostic dilemma involving 45,X, 46,XY, and 47,XYY cell lines.

Discrepancies between cytogenetic findings in chorionic villi (CV) and fetal tissue have been reported. Several embryogenic models have been proposed to explain such discrepancies. We describe a case in which analysis of the direct preparation showed 24% 45,X and 76% 46,XY, with 43% 45,X and 57% 46,XY cells in cultured villi. Amniocentesis results disclosed 97% 46,XY and 3% 47,XYY. No 45,X cells were found in cultured amniocytes. These findings suggest that nondisjunction occurred early in postzygotic cleavage resulting in 3 cell lines. It is postulated that through selection, the less viable 45,X cells died out among those destined to become fetus proper but persisted among the cytotrophoblast and extraembryonic mesoderm cells. While there is probably selection against all aneuploid cell lines, 47,XYY cells are more likely to survive in the fetus. An explanation for the lack of 47,XYY cells in the CV might be simply that the tissue sampled was not representative of the cytogenetic make up of the entire placenta.

Mosaicism in chorionic villus sampling: an analysis of incidence and chromosomes involved in 2612 consecutive cases.

The incidence of chromosome mosaicism was analysed in 2612 consecutive chorionic villus sampling (CVS) cases. True mosaicism was found in five cases (0.19 per cent). Confined placental mosaicism (CPM) occurred in 51 cases (1.9 per cent). The chromosomes most frequently encountered in CPM were 2, 7, 8, and the sex chromosomes. Three types of CPM as proposed by Kalousek et al. (1992) were observed. Cases with CPM had a statistically significant association with spontaneous abortion (chi 2 = 3.92, p < 0.05). Based on the data analysed, we conclude that (1) CPM is as likely to occur in cultured chorionic villi as in the direct preparation; (2) as with amniocyte culture, chromosome 2 mosaicism occurs commonly in villus culture; (3) the incidence of false-positive results can be greatly reduced and concern about maternal cell contamination can be alleviated by using both direct cytotrophoblast preparation and cultured chorionic stroma cells in all cases; and (4) follow-up cytogenetic and obstetrical studies, such as ultrasound and fetal monitoring, should always be considered in cases where CPM is suspected.

Chorionic villus sampling: experience with 3016 cases performed by a single operator.

OBJECTIVE: To describe our experience with 3016 first-trimester chorionic villus sampling (CVS) procedures, all performed by a single operator, to assess the influence of operator experience on the safety and efficacy of CVS. METHODS: Transcervical or transabdominal CVS procedures were performed on 3016 patients between the gestational ages of 9-12 weeks. The sampling success rate, procedure complications, cytogenetic results, and pregnancy outcomes were tabulated and analyzed. RESULTS: Samples adequate for diagnosis were obtained in 99.7% of the cases. The mean (+/- standard deviation) number of insertions per procedure was 1.1 +/- 0.4. The percentage of procedures in which the sample was obtained with a single insertion increased from 51% in the first 100 cases to 96% in the last 2516 cases. There were 56 (1.94%) first- and second-trimester pregnancy losses among 2892 pregnancies intended to continue. This loss rate compares with published baseline risk figures for miscarriage of approximately 2-3%. No difference in pregnancy loss rate followed one or two catheter or needle insertions, but the need for three insertions was associated with a significantly increased loss rate (6.7 versus 1.9%; chi 2 = 4.35, P < .05). CONCLUSION: Operator experience plays a significant role in the safety and efficacy of CVS.

Apparent non-mosaic trisomy 16 in chorionic villi: diagnostic dilemma or clinically significant finding?

A case is presented in which apparent non-mosaic trisomy 16 was found in chorionic villi (direct and culture) obtained from a patient undergoing first-trimester prenatal diagnosis. The fetal karyotype subsequently was determined to be 46,XX by follow-up amniocentesis. Serial ultrasonographic examinations revealed placental sonolucencies and intrauterine growth retardation. At 37 weeks, a small-for-gestational-age female was delivered by Caesarean section for fetal distress. Postnatal cytogenetic studies revealed a normal female karyotype in cord blood and mosaic trisomy 16 in placental tissues. These findings suggest that in cases where aneuploidy is confined to placental tissues, it may have biological significance, as evidenced by the apparent placental dysfunction and poor fetal growth in this case.