The University of Michigan Dioxin Exposure Study: estimating residential soil and house dust exposures to young children

Association Between Dioxin and Metabolic Syndrome by Age and Sex in an Endemic Area of Exposure in Taiwan

BACKGROUND

Some of the effects of dioxins seem to be different between men and women, and exposures starting at an early age seem to have more prominent effects. Therefore, we conducted a study in Taiwan to evaluate the associations between exposure to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and metabolic syndrome (MetS) starting at different ages in both sexes.

METHODS

We recruited participants from an area where residents were exposed to PCDD/Fs released from a factory and defined serum PCDD/Fs levels ≥20 pg WHO98-TEQDF/g lipid as high dioxin levels. MetS was defined as meeting three of the following criteria: fasting glucose ≥100 mg/dl or under treatment for diabetes, waist circumference ≥90 cm in men or ≥80 cm in women, triglycerides ≥150 mg/dl or under treatment for elevated triglycerides, high-density lipoprotein <40 mg/dl in men or <50 mg/dl in women, and blood pressures ≥130/85 mmHg or under treatment for hypertension.

RESULTS

Of the 2758 participants, 785 patients with MetS were identified, and we observed positive associations between a high dioxin level and MetS. After adjusting for sex, age, and age at starting exposure, we found that a high dioxin level was an independent predictor for MetS (adjusted odds ratio =1.38; 95% confidence interval = 1.11, 1.72). When we stratified the participants by gender, we found that a high dioxin level remained an independent predictor of MetS in men, but not in women, regardless of the age at starting exposure.

CONCLUSIONS

Exposure to PCDD/Fs was associated with MetS in men, independent of age and age at starting exposure.

The bioaccessibility of polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) in cooked plant and animal origin foods

In this study, we compared the effect of boiling and frying food preparation methods in determining the bioaccessibility of polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) in rice, cabbage, milk powder, eggs, beef, and fresh water fish. We then used these data to calculate a toxic equivalent (TEQ) for risk assessment and compared it to published values that did not account for bioaccessibility. When the foods were prepared by boiling, the mean bioaccessibility (%) in rice (PCBs: 16.5±1.0, PCDD/Fs: 4.9±0.3) and cabbage (PCBs: 4.2±0.9, PCDD/Fs: 1.9±0.7) were lower than in animal origin foods (beef, PCBs: 49.0±3.3, PCDD/Fs: 7.8±0.9; egg, PCBs: 29.7±3.1, PCDD/Fs: 8.6±1.3; fish, PCBs: 26.9±2.5, PCDD/Fs: 7.9±1.3; milk powder, PCBs: 72.3±1.6, PCDD/Fs: 28.4±1.2). When fried in cooking oil, the bioaccessibilities of all analytes in all foods increased, but the increase in plant based foods (rice, PCBs: 3.4×, PCDD/Fs: 3.6×; cabbage, PCBs: 10.3×, PCDD/Fs: 7.9×) was greater than that of animal origin foods (beef, PCBs: 1.6×, PCDD/Fs: 3.4×; egg, PCBs: 2.1×, PCDD/Fs: 1.8×; fish, PCBs: 2.8, PCDD/Fs: 3.2×). Comparison of PCBs/PCDD/Fs bioaccessibility in rice and cabbage showed that bioaccessibility was greater in the low fat, high carbohydrate/protein content food (rice) than in the low carbohydrate/protein, low fat content food (cabbage), regardless of the method used to prepare the food. Adjusting for bioaccessibility reduced the gross estimated daily intake (EDI) of 112pgWHO-TEQ/day, by 88% and 63% respectively for foods prepared by boiling and frying. Our results indicate that: 1) The method used for cooking is an important determinant of PCBs/PCDD/Fs bioaccessibility, especially for plant origin foods, 2) there might be a joint fat, carbohydrate and protein effect that influences the bioaccessibilities of PCBs/PCDD/Fs in foods, and 3) use of bioaccessibility estimates would reduce the uncertainty in TEQ calculations.

Association between Blood Dioxin Level and Chronic Kidney Disease in an Endemic Area of Exposure

BACKGROUND

Dioxin is an industrial pollutant related to various diseases, but epidemiological data on its effects on the kidney are limited. Therefore, we conducted a study to evaluate the association between dioxin exposure and chronic kidney disease (CKD) and identify the related factors.

METHODS

We conducted a community-based cross-sectional study and recruited participants from an area where the residents were exposed to dioxin released from a factory. We defined a "high dioxin level" as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) ≥ 20 pg WHO98-TEQDF/g lipid in the serum and defined CKD as having an estimated glomerular filtration rate (e-GFR) ≤ 60 mL/min/1.73m2 or a diagnosis of CKD by a physician. The renal function was assessed between 2005 and 2010, and we excluded those who had had kidney diseases before the study started. Comparisons between patients of CKD and those who did not have CKD were made to identify the risk factors for CKD.

RESULTS

Of the 2898 participants, 1427 had high dioxin levels, and 156 had CKD. In the univariate analyses, CKD was associated with high dioxin levels, age, gender, metabolic syndrome, diabetes mellitus, hypertension, and high insulin and uric acid levels. After adjusting for other factors, we found high dioxin levels (adjusted odds ratio [AOR] = 1.76, 95% confidence interval [CI]: 1.04-2.99), female gender (AOR = 1.74, 95%CI: 1.20-2.53), hypertension (AOR = 1.68, 95%CI: 1.17-2.42), high insulin levels (AOR = 2.14, 95% CI: 1.26-3.61), high uric acid levels (AOR = 4.25, 95% CI: 2.92-6.20), and older age (AOR = 4.66, 95% CI: 1.87-11.62 for 40-64 year and AOR = 26.66, 95% CI: 10.51-67.62 for age ≥ 65 year) were independent predictors of CKD.

CONCLUSION

A high dioxin level was associated with an increased prevalence of CKD. Therefore, the kidney function of populations with exposure to dioxin should be monitored.

Association between Dioxin and Diabetes Mellitus in an Endemic Area of Exposure in Taiwan: A Population-Based Study

Dioxin has been recognized as an environmental endocrine disruptor, but epidemiology studies of its effects on type 2 diabetes mellitus (DM) found inconsistent results, especially in men. Therefore, we conducted a study in Taiwan to evaluate the association between exposure to dioxin and DM.We recruited participants in an area where the residents were exposed to dioxin released from a factory. Using 20 and 64 pg WHO98-TEQDF/g lipid as the cut-offs, we categorized participants into 3 groups according to the level of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the serum. We defined DM as a fasting plasma glucose level more than 126 mg/dl or an existing diagnosis.Of the 2898 participants, 425 patients of DM were identified, and we observed positive associations between dioxin and DM. After adjusting for age and body mass index (BMI), we found that a high serum dioxin level was an independent risk factor for DM (adjusted odds ratio [AOR] associated with 20-63 pg WHO98-TEQDF/g lipid = 2.1, 95% confidence interval [95% CI] 1.5-2.9; AOR for ≥64 pg WHO98-TEQDF/g lipid = 3.2, 95% CI 2.1-4.8). The findings are compatible with those in previous studies of PCDD/Fs. When we stratified the participants by sex, the serum dioxin level remained an independent risk factor for DM in both men and women.Exposure to dioxin is a risk factor for DM, independent of age and BMI in both men and women. Therefore, screening and intervention programs should be considered in endemic areas of exposure to dioxin.

PCDD/Fs in the soils in the province of Trento: 10 years of monitoring

This paper presents a 10-year overview of the dioxins and furans (PCDD/Fs) content in soils in the province of Trento (Italy). The aim was to compare the results found in the Valsugana valley where there is a steel-making plant with other locations within the province. During 2002 and from 2005 to 2010, campaigns were carried out in order to obtain a background reference in terms of micropollutants, in view of the possible construction of a municipal solid waste (MSW) incinerator in Trento. In 2009, a campaign was performed for the environmental characterization of the Valsugana valley, the town of Trento and its surroundings, in order to help assess the impact of the steel-making plant. In 2012, another campaign was carried out by the Department of Civil and Environmental Engineering of Trento, in order to monitor the soils in the area around the steel mill. All the campaigns showed relatively low concentrations of PCDD/Fs, both in protected areas and in the areas close to the industrial plants. No critical situations were identified, as also confirmed by an estimation of the potential daily PCDD/F intake by children subject to accidental ingestion of soil.