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Environmental Health Perspectives Nov 2008In this systematic review we evaluated the evidence on the association between dioxin exposure and cardiovascular disease (CVD) mortality in humans. (Review)
Review
OBJECTIVE
In this systematic review we evaluated the evidence on the association between dioxin exposure and cardiovascular disease (CVD) mortality in humans.
DATA SOURCES AND EXTRACTION
We conducted a PubMed search in December 2007 and considered all English-language epidemiologic studies and their citations regarding dioxin exposure and CVD mortality. To focus on dioxins, we excluded cohorts that were either primarily exposed to polychlorinated biphenyls or from the leather and perfume industries, which include other cardiotoxic coexposures.
DATA SYNTHESIS
We included results from 12 cohorts in the review. Ten cohorts were occupationally exposed. We divided analyses according to two well-recognized criteria of epidemiologic study quality: the accuracy of the exposure assessment, and whether the exposed population was compared with an internal or an external (e.g., general population) reference group. Analyses using internal comparisons with accurate exposure assessments are the highest quality because they minimize both exposure misclassification and confounding due to workers being healthier than the general population ("healthy worker effect"). The studies in the highest-quality group found consistent and significant dose-related increases in ischemic heart disease (IHD) mortality and more modest associations with all-CVD mortality. Their primary limitation was a lack of adjustment for potential confounding by the major risk factors for CVD.
CONCLUSIONS
The results of this systematic review suggest that dioxin exposure is associated with mortality from both IHD and all CVD, although more strongly with the former. However, it is not possible to determine the potential bias, if any, from confounding by other risk factors for CVD.
Topics: Cardiovascular Diseases; Cohort Studies; Dioxins; Humans
PubMed: 19057694
DOI: 10.1289/ehp.11579 -
Annals of Oncology : Official Journal... Feb 2009In overviews concerning environmental cancers, the definition of 'environmental' can vary considerably in terms of the list of exposures considered, due to differences... (Review)
Review
In overviews concerning environmental cancers, the definition of 'environmental' can vary considerably in terms of the list of exposures considered, due to differences in inclusion criteria, and the articles tend to focus mainly or exclusively on Western populations. International agencies such as World Health Organisation, that have had considerable success in fighting infectious diseases, seem to be weaker when considering the relevance of environmental carcinogens, particularly in developing countries, and in identifying the exposed populations. The purpose of this paper is to reexamine the issue with a specific focus on developing countries. There are good reasons to believe that the burden of environmental cancers in such countries is high and has been underestimated in previous analyses. We examine the most common pollutants (aflatoxins, arsenic, air pollutants, biomass fuel and coal, polychlorinated biphenyls and wastes). A systematic review was not possible given the sparse nature of the data, but we suggest that the burden of environmental exposures to carcinogens can be substantial in developing countries.
Topics: Developing Countries; Environmental Exposure; Environmental Monitoring; Environmental Pollutants; Epidemiological Monitoring; Humans; Neoplasms
PubMed: 18854551
DOI: 10.1093/annonc/mdn596 -
Gaceta Sanitaria 2008No systematic review is available on studies conducted in Spain on human concentrations of persistent toxic substances (PTS). The objectives were: to identify studies... (Review)
Review
No systematic review is available on studies conducted in Spain on human concentrations of persistent toxic substances (PTS). The objectives were: to identify studies conducted in Spain in the past 30 years that determined concentrations in humans of dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethane (DDE), hexachlorobenzene (HCB), hexachlorocyclohexane (HCH) and polychlorinated biphenyls (PCBs); and to summarize the main characteristics and results of each study. Studies are highly heterogeneous and most lack population representativeness. Concentrations of DDT and DDE might have decreased moderately in the last 20 years. Numerous fluctuations are apparent in levels of HCB, HCHs and PCBs, in some instances compatible with some stagnation. There are enormous differences in levels detected across and within studies: PTS concentrations of some individuals may be over 200-fold higher than those of others. The actual magnitude of human contamination by PTS and their trends across Spain -as well as the geographic and social heterogeneity- remain largely unknown.
Topics: Hazardous Substances; Humans; Spain
PubMed: 18579052
DOI: 10.1157/13123971 -
Journal of Epidemiology and Community... Aug 2001Polychlorinated biphenyls (PCBs) are complex mixtures of persistent contaminants that are widespread in the environment. Newborns are exposed across the placenta and... (Review)
Review
BACKGROUND
Polychlorinated biphenyls (PCBs) are complex mixtures of persistent contaminants that are widespread in the environment. Newborns are exposed across the placenta and through breast feeding. Experimental animal studies have indicated that PCBs are neurotoxic. The neurological effects of these compounds on children are not clear.
METHODS
A systematic review of literature on the relation between neurological development in children and exposure to polychlorinated biphenyls.
RESULTS
Seven follow up studies evaluated the effect of prenatal exposure to PCBs. Two of these studies evaluated highly exposed children. In newborns, an increase of the abnormal reflexes was observed in all four studies evaluating it. During the first months of life, a decrease in motor skills was observed in four of the five studies that investigated psychomotor development; deficits in the acquisition of cognitive skills were observed only in one study assessing non-highly exposed populations. At 4 years of age, an effect on the cognitive areas was observed in four of the five studies that evaluated it. Postnatal exposure to PCBs through breast feeding was not clearly related to any effect on neurological development.
CONCLUSIONS
These studies suggest a subtle adverse effect of prenatal PCBs exposure on child neurodevelopment. Differences in study design, inconsistency in some of the results, and the lack of adequate quantitative exposure data, do not allow the derivation of the degree of risk associated with neurodevelopmental effects at current levels of exposure.
Topics: Breast Feeding; Child; Child, Preschool; Cognition Disorders; Developmental Disabilities; Female; Humans; Infant; Infant, Newborn; Maternal Exposure; Maternal-Fetal Exchange; Motor Skills Disorders; Polychlorinated Biphenyls; Pregnancy; Psychomotor Disorders
PubMed: 11449010
DOI: 10.1136/jech.55.8.537