Department of Environmental Medicine, Institute of Public Health (C.A.G.T., L.I.R., C.D., P.G., F.N., T.K.J.), and Institute of Sports Science and Clinical Biomechanics (A.G., M.R.-L., L.B.A.), University of Southern Denmark, 5000 Odense C, Denmark; and Department of Biostatistics (K.D.S., T.S.), University of Copenhagen, 1353 Copenhagen, Denmark.
Our objective was to explore whether childhood exposure to perfluorinated and polyfluorinated compounds (PFCs), widely used stain- and grease-repellent chemicals, is associated with adiposity and markers of glycemic control.
Body mass index, skinfold thickness, waist circumference, leptin, adiponectin, insulin, glucose, and triglyceride concentrations were assessed in 8- to 10-year-old children in 1997 in a subset of the European Youth Heart Study, Danish component. Plasma PFC concentrations were available from 499 children. Linear regression models were performed to determine the association between PFC exposure and indicators of adiposity and markers of glycemic control.
There was no association between PFC exposures and adiposity or markers of glycemic control in normal-weight children. Among overweight children, an increase of 10 ng perfluorooctane sulfonic acid/mL plasma was associated with 16.2% (95% confidence interval [CI], 5.2%-28.3%) higher insulin concentration, 12.0% (95% CI, 2.4%-22.4%) higher ß-cell activity, 17.6% (95% CI, 5.8%-30.8%) higher insulin resistance, and 8.6% (95% CI, 1.2%-16.5%) higher triglyceride concentrations, and an increase of 10 ng perfluorooctanoic acid/mL plasma was associated with 71.6% (95% CI, 2.4%-187.5%) higher insulin concentration, 67.5% (95% CI, 5.5%-166.0%) higher ß-cell function, 73.9% (95% CI, 0.2%-202.0%) higher insulin resistance, and 76.2% (95% CI, 22.8%-153.0%) higher triglyceride concentrations.
Increased PFC exposure in overweight 8- to 10-year-old children was associated with higher insulin and triglyceride concentrations. Chance findings may explain some of our results, and due to the cross-sectional design, reverse causation cannot be excluded. The findings therefore need to be confirmed in longitudinal studies.
This study aims to assess the atmospheric concentrations of methylcyclopentadienyl manganese tricarbonyl (MMT), respirable manganese (MNR) and total manganese (MnT) in certain specific microenvironments and to provide an estimation of human exposure to MnR. Sampling was carried out in five microenvironments: a gas station, an underground car park, downtown Montreal, near an expressway and near an oil refinery. The samples were collected using Gil-Air portable pumps during three days and were analyzed by instrumental neutron activation analysis (INAA). The mean concentrations of MnR, MnT and MMT were 0.036 microgram m-3, 0.103 microgram m-3 and 0.005 microgram m-3 respectively. The MnR/MnT ratios vary from 25% to 43% (mean 35%) while the MMT/MnT ratios averaged about 5%. Furthermore, the mean concentration of the MnR measured near the expressway (0.053 microgram m-3) is similar to the United States Environmental Protection Agency (U.S. EPA) reference concentration (RfC = 0.05 microgram m-3). The average daily environmental exposure dose to MNR is estimated at 0.010 microgram kg-1 d-1 and its contribution to the multimedia exposure (air, food and water) is low. The overall results show a lack of potential exposure to MMT and substantial concentrations of MnR near an expressway.
Days of high ambient carbon dioxide (CO) have been associated with increased hospital admissions for cardiac disease. This study was conducted to determine if daily concentrations of CO and fine particulates (PM2.5) are associated with daily changes in heart rate variability.
Each of 36 adults with coronary artery disease had personal exposure to PM2.5 and CO measured along with heart rate variability for one 24-hour period each week for up to 10 weeks.
Among those not taking beta-receptor blockers, there was a positive association between the standard deviation of the R-to-R intervals and CO (P = 0.02). No effect was found for PM2.5.
Urban exposure to CO may exert a biologic effect on the heart, which may be modified by medications.
An investigation of ambient levels and sources of volatile organic compounds (VOCs) and associated public health risks was carried out at two northern Alberta oil sands communities (Fort McKay and Fort McMurray located?30?km from oil sands development, respectively) for the period January 2010-March 2015. Levels of total detected VOCs were comparatively similar at both communities (Fort McKay: geometric mean?=?22.8?µg/m3, interquartile range, IQR?=?13.8-41?µg/m3); (Fort McMurray: geometric mean?=?23.3?µg/m3, IQR?=?12.0-41?µg/m3). In general, methanol (24%-50%), alkanes (26%-32%) and acetaldehyde (23%-30%) were the predominant VOCs followed by acetone (20%-24%) and aromatics (~9%). Mean and maximum ambient concentrations of selected hazardous VOCs were compared to health risk screening criteria used by United States regulatory agencies. The Positive matrix factorization (PMF) model was used to identify and apportion VOC sources at Fort McKay and Fort McMurray. Five sources were identified at Fort McKay, where four sources (oil sands fugitives, liquid/unburned fuel, ethylbenzene/xylene-rich and petroleum processing) were oil sands related emissions and contributed to 70% of total VOCs. At Fort McMurray six sources were identified, where local sources other than oil sands development were also observed. Contribution of aged air mass/regional transport including biomass burning emissions was ~30% of total VOCs at both communities. Source-specific carcinogenic and non-carcinogenic risk values were also calculated and were below acceptable and safe levels of risk, except for aged air mass/regional transport (at both communities), and ethylbenzene/xylene-rich (only at Fort McMurray).
Cadmium (Cd), a nonessential toxic metal present in the environment, accumulates in the organs of herbivorous mammals which typically are consumed by Aboriginal populations. The relative contribution of this potential exposure source to concentrations of blood Cd was investigated in 1429 participants (age >7 years) residing in the nine Cree First Nations communities of Eeyou Istchee, northern Quebec, Canada. Analysis of variance identified significant Cd concentration differences between communities, sex, and age groups, although these were complicated by significant 2-way interactions. The percentage of participants with Cd concentrations within the adopted health-based guideline categories of 'acceptable', 'concern' and 'action' pertaining to kidney damage was 56.2%, 38.3%, and 5.5%, respectively. Partial correlations (controlling for age as a continuous variable) did not show a significant association between consumption of traditional foods and Cd concentrations (r = 0.014, df = 105, p = 0.883). A significant and positive partial correlation (r = 0.390, df = 105, p
We are daily exposed to many different environmental contaminants. Mixtures of these contaminants could act together to induce more pronounced effects than the sum of the individual contaminants. To evaluate the effects of such mixtures, it is of importance to assess the co-variance amongst the contaminants. Thirty-seven environmental contaminants representing different classes were measured in blood samples from 1016 individuals aged 70 years. Hierarchical cluster analysis and principal component analysis were used to assess the co-variation among the contaminants. Within each identified cluster, possible marker contaminants were sought for. We validated our findings using data from the National Health and Nutrition Examination Survey (NHANES) 2003-2004 study. Two large clusters could be identified, one representing low/medium chlorinated polychlorinated biphenyls (PCBs) (=6 chlorine atoms), as well as two pesticides and one representing medium/high chlorinated PCBs (=6 chlorine atoms). PCBs 118 and 153 could be used as markers for the low/medium chlorinated cluster and PCBs 170 and 209 could be used as markers for the medium/high chlorinated cluster. This pattern was similar to data from the NHANES study. Apart from the PCBs, little co-variation was seen among the contaminants. Thus, a large number of chemicals have to be measured to adequately identify mixtures of environmental contaminants.
A review and analysis of published information combined with the results of recent gamma ray surveys were used to determine the annual effective dose to Canadians from natural sources of radiation. The dose due to external radiation was determined from ground gamma ray surveys carried out in the cities of Toronto, Ottawa, Montreal and Winnipeg and was calculated to be 219 microSv. A compilation of airborne gamma ray data from Canada and the United States shows that there are large variations in external radiation with the highest annual outdoor level of 1424 microSv being found in northern Canada. The annual effective inhalation dose of 926 microSv from 222Rn and 220Rn was calculated from approximately 14,000 measurements across Canada. This value includes a contribution of 128 microSv from 222Rn in the outdoor air together with 6 microSv from long-lived uranium and thorium series radionuclides in dust particles. Based on published information, the annual effective dose due to internal radioactivity is 306 microSv. A program developed by the Federal Aviation Administration was used to calculate a population-weighted annual effective dose from cosmic radiation of 318 microSv. The total population-weighted average annual effective dose to Canadians from all sources of natural background radiation was calculated to be 1769 microSv but varies significantly from city to city, largely due to differences in the inhalation dose from 222Rn.
Current doses arising from external and internal pathways have been estimated for the residents of two villages, Muslumovo and Brodokalmak, alongside the Techa River, which was contaminated by radioactive releases from the Mayak production facility. The dose estimates are based on numerous environmental measurements supplemented by further human whole body measurements and studies on occupational and dietary habits of Slavic and Turkish ethnic groups. Estimated doses arise mainly from use of the contaminated floodplains alongside the Techa River. The current average annual effective dose attributable to Cs and Sr in the environment, under conditions where restrictions on some river-related activities are in place, may exceed the Russian national action level of 1 mSv only in the hypothetical critical group of herdsmen in Muslumovo. The dose to this critical group in Brodokalmak is assessed to be 3 times less than that in Muslumovo and 2 fold below the action level. The external and internal exposures give comparable contributions to the total dose in both settlements and population groups: 47% and 53% in Muslumovo and 40% and 60% in Brodokalmak, respectively. About one quarter to one half of the internal dose in adults arises from the intake of Sr. In order to avoid substantial increases in the dose received by Muslumovo residents, it is expedient to prolong the current policy of restriction of some river-related population activities in this village.
The aim of this study was to evaluate hexachlorocyclohexane (HCH) exposure in children living in nine hot spots in four Mexican states. We analyzed HCH (a, ß, and ?-isomers) in blood using gas chromatography/mass spectrometry. HCH exposure level in 261 children was assessed and approximately 75 % of the children studied had detectable levels of HCH. These levels ranged from 188 to 40,096.7 ng/g lipid. The highest mean levels were found in Lacanja (5,446.9 ng/g lipid), an indigenous community in Chiapas, Mexico. Our data indicate high exposure to HCH in children living in these communities.
Results from animal and human studies suggest that lithium in therapeutic doses may improve learning and memory and modify the risk of developing dementia. Additional preliminary studies suggest that subtherapeutic levels, including microlevels of lithium, may influence human cognition.
To investigate whether the incidence of dementia in the general population covaries with long-term exposure to microlevels of lithium in drinking water.
This Danish nationwide, population-based, nested case-control study examined longitudinal, individual geographic data on municipality of residence and data from drinking water measurements combined with time-specific data from all patients aged 50 to 90 years with a hospital contact with a diagnosis of dementia from January 1, 1970, through December 31, 2013, and 10 age- and sex-matched control individuals from the Danish population. The mean lithium exposure in drinking water since 1986 was estimated for all study individuals. Data analysis was performed from January 1, 1995, through December 31, 2013.
A diagnosis of dementia in a hospital inpatient or outpatient contact. Diagnoses of Alzheimer disease and vascular dementia were secondary outcome measures. In primary analyses, distribution of lithium exposure was compared between patients with dementia and controls.
A total of 73?731 patients with dementia and 733?653 controls (median age, 80.3 years; interquartile range, 74.9-84.6 years; 44 760 female [60.7%] and 28 971 male [39.3%]) were included in the study. Lithium exposure was statistically significantly different between patients with a diagnosis of dementia (median, 11.5 µg/L; interquartile range, 6.5-14.9 µg/L) and controls (median, 12.2 µg/L; interquartile range, 7.3-16.0 µg/L; P?