Heavy metal concentrations in great blue heron fecal castings in Washington State: a technique for monitoring regional and global trends in environmental contaminants.
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Congener-specific PCB analysis allows use of toxic equivalency (TEQ) TCDD-based risk assessment approaches when analytical methods are sufficiently sensitive. Many efforts to analyze fish samples for PCB congeners report the majority of samples as non-detects; these data are of little use for human health risk assessment if the limits of analytical detection exceed levels of potential health concern. However, increasing analytical sensitivity is costly and technically difficult. An approach to assess analytical sensitivity needs for risk assessment by defining toxicological endpoints of concern and acceptable risk levels is presented. This framework was applied to assessment of potential PCB TEQ cancer risks to the general United States population and tribal consumers of Columbia River fish, but may be easily adjusted for other situations. A probabilistic model was used to calculate the necessary analytical sensitivity for PCB TEQ cancer risk assessment using the Environmental Protection Agency's new draft cancer risk slope factor for TCDD and fish consumption data. Desired levels of analytical sensitivity were estimated for the congener expected to contribute the most to PCB TEQ, PCB 126, and compared to limits of detection for various analytical methods. The financial and health value of methods with different levels of analytical sensitivity were compared using a value of information approach, which includes analytical cost and cost of potential health outcomes, and a proposed risk assessment utility approach which considers the relative health protectiveness of analytical options non-monetarily. Sensitivity analyses indicate that average consumption rate, cancer risk slope factor choice, and knowledge of existing PCB contamination are important considerations for planning PCB congener analysis.
A number of studies have suggested that environmental contamination with organochlorine pesticides may be related to risk of breast cancer. To investigate this association in a rural part of Australia, organochlorine contamination data from a breast milk organochlorine study conducted in the state of Victoria in 1993 were used. The state was divided into 11 statistical divisions. Standardized incidence ratios (SIRs) for the 11 regions were calculated using breast cancer incidence data from 1983 to 2002. During that time, 47,250 breast cancer cases occurred in Victoria, which had an average population of 2,147,409 women. The Ovens-Murray region, which was the region most contaminated with organochlorine pesticides, showed an elevated SIR of 1.10 (95%CI, 1.03-1.17), although two other regions with lower organochlorine contamination levels also had elevated SIRs. The rural part of the Ovens-Murray region, where the main pesticide use occurred, had the highest SIR, 1.15 (95%CI, 1.07-1.23). We did not find any significant correlation between organochlorine contamination and the age-standardized rate of breast cancer across all regions. But a positive dose-response relationship using an adjusted negative binomial model was detected for heptachlor epoxide. Our study may provide limited support for the role of environmental contamination with organochlorine pesticides in the development of breast cancer.
We have determined the concentrations of lead (Pb), cadmium (Cd), and mercury (Hg) in the blood of children living in two Andean villages in Ecuador with many family-owned cottage-type industries using Pb from discarded car batteries and occasionally, utility batteries containing Cd and Hg for the production of glazed tiles. The battery metals are ground together with water to a suspension, which is applied manually onto the tiles and then fused at about 1,200 degrees C in sawdust-fired kilns. Children aged 4-15 years were recruited from the schools with the assistance of the school-teachers. Children from homes with and without tile-glazing activities were to be included. Blood metal concentrations were determined by inductively coupled plasma mass spectrometry (ICP-MS). The children had extremely high blood lead concentrations (B-Pb), which ranged between 100 and 1,100 micrograms/l (median 510 micrograms/l, n = 82). Children from families engaged in tile-glazing production had significantly higher B-Pb (median 600 micrograms/l) than those living in homes with no such activity (median 210 micrograms/l), although the B-Pb of the latter were nonetheless clearly elevated. B-Cd and B-Hg were low (medians 0.25 microgram Cd/l and 1.6 micrograms Hg/l, respectively), indicating that the exposure from utility batteries containing Cd and Hg was low. The blood hemoglobin concentrations decreased significantly with rising B-Pb, indicating an effect on the heme synthesis. This was supported by a marked increase in the blood concentration of protoporphyrins with increasing B-Pb. It can be concluded that children from families with cottage industries producing glazed tiles are at risk for severe health effects due to high lead exposure.
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UNLABELLED: Campo de Jales is a village surrounding the abandoned Jales mine. The area is heavily contaminated with heavy metals and dusts from large tailings piles as result of centuries of mining operations. The aim of this study is to investigate potential health threats associated with site contamination. The population studied comprised two groups: people living in Campo de Jales (n = 229) and a control group - people living in Vilar de Macada (n = 234). Lead and cadmium exposure and symptoms survey were carried out. The results showed a significant higher levels of blood lead and cadmium between the Campo de Jales residents (lead: 9.5 microgr/dl versus 7.7 microgr/dl; cadmium: 0.84 microgr/dl versus 0,65 microgr/dl) as well as to a higher prevalence of respiratory and irritation symptoms and great concern about his own health. IN CONCLUSION: community is the scene of long-term health problems resulting from the site environmental contamination.
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Endometriosis has been hypothesised to be linked to persistent and toxic organochlorinated chemicals. Dioxins and dioxin-like compounds have in particular been associated with the disease, mainly on the basis of experimental studies. Data in women are conflicting. A case-control study on 80 Italian nulliparous women of reproductive age was carried out to assess whether there is a correlation between the presence of endometriosis and blood levels of polychlorobiphenyls (PCBs), a family of ubiquitary environmental pollutants which comprises congeners with dioxin-like activity. Higher levels of PCBs were found in women with endometriosis. A mean cumulative value of 410 ng g(-1), lipid base, was found in cases versus the value of 250 ng g(-1) observed in the control group (odds ratio for upper tertile 4.0, CI 95% 1.3-13; p = 0.0003). PCB increase involved both dioxin-like (PCBs 105, 118, 156, and 167) and non-dioxin-like congeners (PCBs 101, 138, 153, 170, 180).
The cement dust is one of the causes of pollution in the environment. In the present study, the cadmium concentrations of soil and plant specimens taken from a rural area exposed to cement factory emissions were determined and also the blood concentrations and sensitivity conditions in humans residing in this rural area were investigated. The 108 soil (36 for control) and plant specimens were collected from eight different directions of the cement plant located in Cukurhisar town in Eskişehir city. Blood samples of the individuals residing in this area were taken from 258 subjects (258 for control) following a physical examination, and patch tests were also applied. The results show that the cadmium concentrations of the soil and plant specimens taken from different places in different directions of the factory were higher than in the control areas. The physical examination of subjects did not reveal results different from those of the control group except for the diagnosis of contact dermatitis. The analysis of venous blood samples showed that cadmium concentrations were found to be within the reference values given for both groups, but higher in the subjects (p<0.001). According to the results of patch tests, sensitivity to cadmium was found to be more frequent for the subject group than the control group (p<0.05). Those results show that, although clinical tools revealed no toxic effects for the subject, except contact dermatitis, the cement plant increases cadmium pollution on the surrounding environment.
A 4-year longitudinal study is being conducted to evaluate potential changes to the environment and exposure of young children associated with the introduction of methylcyclopentadienyl manganese tricarbonyl (MMT) into Australia in 2001. The cohort consists of 57 females and 56 males, with an age range of 0.29-3.9 years. Samples are collected every 6 months from children in residences located at varying distances from major traffic thoroughfares in Sydney. Environmental samples include air, house, and daycare center dustfall, soil, dust sweepings, and gasoline; samples from the children include blood, urine, handwipes prior to and after playing outdoors, and a 6-day duplicate diet. All samples are analyzed for a suite of 20 elements using inductively coupled plasma methods. Results are presented for the first three 6-month sampling periods for lead (Pb) and manganese (Mn). For dustfall accumulation, expressed as metal concentration/m2/30 days, there was no significant difference between homes and daycare centers for either Pb or Mn, no significant change over the three sampling periods (time) for Pb or Mn, and a positive relationship between "traffic exposure" (traffic volume and proximity to the road) and Pb but not Mn. Lead concentrations in soil was a significant predictor for Pb in the house dustfall. For handwipes, the concentrations of Pb and Mn in wipes taken from children after playing outdoors was usually significantly greater than those for wipes taken prior to playing. There was no significant association between the concentrations of either Pb or Mn in handwipes and traffic exposure, and there was no significant association between Pb concentrations in the handwipes and gender, although the latter showed a marginally significant association for Mn (P = 0.053). Age was related to Pb level in the handwipes, with older subjects having higher Pb levels, and there were significant decreases in Pb and Mn concentrations over time. Dustfall accumulation was a significant predictor for Pb in the handwipes, and dust sweepings were a significant predictor of Mn in handwipes. Blood lead (PbB) concentrations ranged from 0.6 to 19 microg/dL (GM 2.6) (n = 269), and manganese in blood (MnB) ranged from 1.8 to 45 microg/L (GM 11.6) (n = 254). There was no significant difference between females and males for either mean PbB or MnB; over time there was a significant decline in PbB but no significant change in MnB. The only significant predictor for PbB was dustfall accumulation, although dietary intake may also be important, and the only significant predictor for MnB was Mn in handwipes prior to playing. At this early stage of the investigation we have not been able to detect any increases in Mn in these environmental samples or blood samples potentially associated with the use of MMT; in fact the Mn levels in handwipes declined over time.
Arsenic, cadmium, lead, and mercury are neurotoxins, and some studies suggest that these elements might also be teratogens. Using a case-control study design, we investigated the relation between exposure to these heavy metals and neural tube defects (NTDs) in offspring of Mexican-American women living in 1 of the 14 Texas counties bordering Mexico. A total of 184 case-women with NTD-affected pregnancies and 225 control-women with normal live births were interviewed about their environmental and occupational exposures during the periconceptional period. Biologic samples for blood lead and urinary arsenic, cadmium, and mercury were also obtained for a subset of these women. Overall, the median levels of these biomarkers for heavy metal exposure did not differ significantly (P > 0.05) between case- and control-women. However, among women in the highest income group, case-women were nine times more likely (95% confidence interval (CI) 1.4-57) than control-women to have a urinary mercury 5.62 microg/L. Case-women were 4.2 times more likely (95% CI 1.1-16) to report burning treated wood during the periconceptional period than control-women. Elevated odds ratios (ORs) were observed for maternal and paternal occupational exposures to arsenic and mercury, but the 95% CIs were consistent with unity. The 95% CIs of the ORs were also consistent with unity for higher levels of arsenic, cadmium, lead, and mercury in drinking water and among women who lived within 2 miles at the time of conception to industrial facilities with reported emissions of any of these heavy metals. Our findings suggest that maternal exposures to arsenic, cadmium, or lead are probably not significant risk factors for NTDs in offspring. However, the elevated urinary mercury levels found in this population and exposures to the combustion of treated wood may warrant further investigation.
Humans are exposed to many environmental chemicals, some of which can potentially affect neurodevelopment. Fetuses, infants, and young children are the most susceptible to the effects of these chemicals. As part of the National Health and Examination Survey, 1999-2000, the Centers for Disease Control and Prevention analyzed biological samples for many of these chemicals in a representative sampling of the U.S. population. Concentration data of selected metals, persistent organic pollutants, organophosphorus and carbamate insecticides, and cotinine are presented. For example, the 95th percentile estimates for serum total PCBs (whole weight) in the population aged 20 years and older is about 2.7 ng/g. The 95th percentile estimates for serum dioxin total toxic equivalence in the U.S. population aged 20 years and older is between 40 and 50 pg/g lipid basis. In general, human levels of these chemicals are decreasing over time in the U.S. population. This reflects the effects of legislation, industry efforts, and changes in lifestyle/activity patterns in the U.S. population. These data will continue to be collected in 2-year cycles and thus allow changes in human levels to be followed.
Biomonitoring programs, such as those being conducted at the Centers for Disease Control and Prevention in conjunction with the National Health and Nutrition Examination Survey (NHANES), are of benefit to all disciplines of environmental public health. However, all programs have limitations, and like most things in science, "One size does not fit all." We point out some of these limitations, particularly those dealing with the amount of biological sample available from various age groups and the specificity of the exposure assessment. We recommend additional studies to supplement the NHANES biomonitoring data.
The main objective of this study was to establish background levels of serum PCDD/Fs and biochemistry of residents living near municipal waste incinerators (MWIs) which had been operating between 1 and 8 years, and also to examine the association between the serum PCDD/Fs levels and health outcomes of interest. Information on medical history, life-style, and dietary habits was obtained by questionnaire interview. Significantly elevated levels of glucose and blood urea nitrogen (BUN) were found in those with low to high serum PCDD/Fs levels (p<0.05), and PCDD/Fs levels were found to be positively associated with glucose levels, and marginally with GGT levels even after adjusting for age, sex, BMI and smoking status. Although no conclusive findings on health disorder were associated with the accumulation of serum PCDD/Fs in our study participants, we suggest that the current biochemistry examinations only reflect partially the physiological change in glucose modulation and liver function. However, the low serum PCDD/Fs level does not seem to be sufficient in eliciting pathological process for diabetes or liver-related diseases. The findings suggest that the human body's biochemistry functions such as liver and glucose modulation were affected by PCDD/Fs exposure at even these low serum PCDD/Fs levels found in the general population. Other biochemical functions therefore should be further analyzed, especially for hormone-related and immune functions.
We assessed the spatial variation of fluoride load on the local ecosystem in the Czech part of the Ore Mountains region and its southern foothills - a heavily polluted part of Europe's "Black Triangle" region. Dental fluorosis in roe deer (Capreolus capreolus) served as a biomarker of fluoride exposure and thus as an indicator of environmental pollution by fluoride. The mean dental lesion index of fluorosis (DLI) calculated from the analyzed mandibles of wild roe deer (>or=2 years of age) was assigned to the hunting ground from which the specimens originated and classified into one of the eight fluorosis categories. Environmental factors potentially related to dental fluorosis (atmospheric deposition of sulfur, concentration of fluoride in and pH of surface waters, geomorphologic features, bedrock and soil type, and vegetation cover), which were represented in the study by GIS layers, were examined to explain the distribution pattern and severity of fluorosis in the roe deer. The study revealed that 75.5% of 616 analyzed mandibles showed dental fluorosis to different extent, with individual DLIs ranging from 0 to 21. The spatial pattern of marked fluorosis on the Czech side continues that found in a previous study on the German side of the Ore Mountains. Together they create a landscape island around several thermal power plants in the region. General Linear Model (GLM) analyses revealed significant relationships between degree of forest damage, soil type, and atmospheric sulfur deposition from air pollution and dental fluorosis, expressed as mean DLI in the roe deer.
East Greenland and Svalbard polar bears (Ursus maritimus) are heavily polluted with long-range transported organochlorines such as PCBs (polychlorinated biphenyls). To investigate the negative health impacts, a time-trend study of skull pathology was conducted on 269 East Greenland and 241 Svalbard polar bears. The skulls were sampled during 1892-2002 and 1964-1992, respectively. Seven different pathological changes were found: adonti, displacement of teeth, caries, osseous proliferations, exostosis, tooth wear and periodontitis. Only tooth wear and periodontitis was in a prevalence that allowed statistical treatment. The most severe cases of tooth wear and periodontitis were accompanied by a substantial loss of alveolar bone structure. The prevalence of tooth wear and periodontitis increased significantly with age (p<0.001) with incisor wear being more severe than in canines, premolars and molars (p<0.001). No sex difference was found for tooth wear (p=0.22) while a significant difference between sexes was found for periodontitis (p=0.01) with males having higher prevalence than females (odds ratio of 2.5 for males:females). In East Greenland, the prevalence of tooth wear was significantly higher in polar bears collected in the pre pollution period (<1960) than in bears sampled during polluted periods (1960-1980 and 1981-2002) (p<0.001). Regarding periodontitis, the prevalence was not significantly different between pre-pollution and pollution periods (p=0.309). Polar bears from Svalbard had significantly higher prevalence of tooth wear (p<0.001) and periodontitis (p=0.02) than polar bears from East Greenland. The tooth wear and periodontitis odds ratios for Svalbard:East Greenland were 135 and 2.6, respectively. Hence, we found a clear age/sex link and geographical difference but no evidence for an association between skull pathology and exposure to organochlorines in East Greenland and Svalbard polar bears.
In an attempt to explain the etiology of frog deformities and population declines, many possible causative factors have been examined, including the input of synthetic chemicals into aquatic systems, where frogs spend much of their lives, including their entire developmental stages. Deformities in populations of green frogs in wetlands of southwestern Michigan that are influenced by agricultural, urban, or industrial inputs were assessed in this study. Of the 1445 green frogs (Rana clamitans) examined, only four (0.3%) exhibited morphological deformities. This deformity rate is less than the recognized background level of deformities for this species, which is approximately 1%. Concentrations of organochlorine insecticides, polychlorinated biphenyls (PCBs), and metals were determined in water, sediment, frog eggs, tadpoles, and adult green frog tissues. Concentrations of all individual organochlorine insecticides in tissue were less than 6 ng/g, wet wt. Concentrations of sigmaPCBs in tissue did not exceed 100 ng/g, wet wt. Concentrations of toxic metals were less than the limits of detection. Because no significant numbers of green frog deformities were observed in this region, it can be assumed that at these low concentrations, physical malformations in green frogs should not be observed. Significance of study. This study provides information on the incidence of deformities in green frog populations in southwestern Michigan and offers background data on chemical residues in green frogs and their environment.