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Environmental Health Perspectives Dec 2002Animal studies indicate that the immune system is one of the most sensitive targets of the toxic effects of 2,3,7,8-tetrachloro-p-dibenzodioxin (TCDD). TCDD inhibits... (Comparative Study)
Comparative Study Review
Animal studies indicate that the immune system is one of the most sensitive targets of the toxic effects of 2,3,7,8-tetrachloro-p-dibenzodioxin (TCDD). TCDD inhibits immunoglobulin secretion and decreases resistance to bacterial, viral, and parasitic infections in exposed animals. Nearly 20 years after the Seveso, Italy, accident, we measured immunoglobulin and complement plasma levels in a random sample of the population in the most highly exposed zones (n = 62) and in the surrounding noncontaminated area (n = 58). Plasma IgG levels decreased with increasing TCDD plasma concentration (r = -0.35, p = 0.0002). Median IgG concentration decreased from 1,526 mg/dL in the group with the lowest (< 3.5 ppt) TCDD levels to 1,163 mg/dL in the group with the highest (20.1-89.9 ppt) TCDD levels (p = 0.002). The association was significant (p = 0.0004) after adjusting for age, sex, smoking, and consumption of domestic livestock and poultry in multiple regression analysis and persisted after exclusion of subjects with inflammatory diseases and those using antibiotics or nonsteroidal anti-inflammatory drugs. IgM, IgA, C3, and C4 plasma concentrations did not exhibit any consistent association with TCDD levels. We performed a systematic review of all the articles published between 1966 and 2001 on human subjects exposed to TCDD reporting information on circulating levels of immunoglobulins and/or complement components. The literature indicates that the evidence for effects of TCDD on humoral immunity is sparse. Methodologic issues, results, and possible sources of variation between studies are discussed. The possible long-term immunologic effects of TCDD exhibited by the participants of the present study, coupled with the increased incidence of lymphatic tumors in the area of the accident, warrant further investigation.
Topics: Accidents; Adult; Aged; Antibody Formation; Carcinogens; Child; Child, Preschool; Environmental Exposure; Female; Follow-Up Studies; Humans; Immunoglobulins; Italy; Lymphoma; Male; Middle Aged; Polychlorinated Dibenzodioxins; Public Health; Risk Assessment
PubMed: 12460794
DOI: 10.1289/ehp.021101169 -
Environmental Health Perspectives Aug 2008Pentachlorophenol, a fungicide widely used as a wood preservative, was classified in 1999 by the International Agency for Research on Cancer as a possible human... (Review)
Review
OBJECTIVE
Pentachlorophenol, a fungicide widely used as a wood preservative, was classified in 1999 by the International Agency for Research on Cancer as a possible human carcinogen. We reviewed currently available data to determine the extent to which recent studies assist in distinguishing the effect of pentachlorophenol from that of its contaminants (e.g., dioxins and other chlorophenols).
DATA SOURCES AND EXTRACTION
We performed a systematic review of published studies pertaining to cancer risk in relation to pentachlorophenol exposure, focusing on results pertaining specifically to all cancer sites and specific hematopoietic cancers, and data pertaining to risks associated with other types of chlorophenols, dioxins, or furans.
SYNTHESIS
The pentachlorophenol studies presented considerable evidence pertaining to hematopoietic cancers, with strong associations seen in multiple studies, in different locations, and using different designs. There is little evidence of an association between these cancers and chlorophenols that contain fewer than four chlorines. The extension of a large cohort study of sawmill workers, with follow-up to 1995, provided information about risks of relatively rare cancers (e.g., non-Hodgkin lymphoma, multiple myeloma), using a validated exposure assessment procedure that distinguishes between exposures to pentachlorophenol and tetrachlorophenol. In contrast with dioxin, pentachlorophenol exposure has not been associated with total cancer incidence or mortality.
CONCLUSIONS
The updated cohort study focusing on pentachlorophenol provides increased statistical power and precision, and demonstrates associations between hematopoietic cancer and pentachlorophenol exposure not observed in earlier evaluations of this cohort. Contaminant confounding is an unlikely explanation for the risks seen with pentachlorophenol exposure.
Topics: Adult; Aged; Aged, 80 and over; Carcinogens; Case-Control Studies; Child; Chlorophenols; Cohort Studies; Dioxins; Environmental Exposure; Female; Fungicides, Industrial; Hematologic Neoplasms; Humans; Incidence; Male; Middle Aged; Pentachlorophenol; Risk Assessment
PubMed: 18709150
DOI: 10.1289/ehp.11081 -
Environment International Feb 2019Endometriosis is a gynaecological disease characterized by the presence of ectopic endometrial tissue that affects women during their reproductive years, having a strong... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Endometriosis is a gynaecological disease characterized by the presence of ectopic endometrial tissue that affects women during their reproductive years, having a strong impact on their lives, fertility and healthcare costs. The aetiology remains largely unknown, but current evidence suggests that it is multi-causal and oestrogen-dependent. Many epidemiologic studies have explored associations between organochlorine chemicals (OCCs) and endometriosis, but the findings are inconsistent.
OBJECTIVES
A systematic review (SR) and meta-analysis were conducted to gather and synthesize all the available evidence from human epidemiological studies about the associations between OCCs and endometriosis.
DATA SOURCES
The searches were conducted in PubMed and Web of Science in June 2016 with a final follow-up in August 2018.
STUDY ELIGIBILITY CRITERIA
Only human epidemiological studies were considered, independent of participant age, body mass index or life-stage. Studies reporting individual measures of exposure to OCCs were included, considering but not limited to polychlorinated dibenzodioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), or organochlorine pesticides (OCPs). The primary health outcome was presence of endometriosis, including all sub-types. Eligibility criteria excluded articles not written in English, conference papers, reviews and studies with overlapping information.
STUDY APPRAISAL AND SYNTHESIS METHODS
A SR protocol pre-registered at PROSPERO was applied in duplicate to gather and extract all eligible original papers from PUBMED and Web of Science databases. Odds ratios were pooled using the inverse variance method for random effects meta-analysis for each group of OCCs. Risk of bias was assessed using the National Toxicology Program/Office of Health Assessment and Translation (NTP/OHAT) Risk of Bias Rating Tool for Human and Animal Studies adapted to the review question. The confidence in the body of evidence and related level of evidence was measured by using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) based NTP/OHAT framework. The results were structured and presented in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.
RESULTS
Of the 51 studies retained for the full-text screening, 17 provided effect sizes and metrics sufficient for pooling estimates through meta-analysis. The overall odds ratios and 95% confidence intervals were 1.65 (1.14; 2.39) for dioxins (n = 10), 1.70 (1.20; 2.39) for PCBs (n = 9), and 1.23 (1.13; 1.36) for OCPs (n = 5). Despite being statistically significant, these estimates should be considered with caution given the notable heterogeneity and small estimated effect size. Misclassification of exposure, due to varying laboratory detection rate capabilities, and disease status, due to varying definitions of endometriosis, were identified as major sources of uncertainty.
LIMITATIONS, CONCLUSIONS, AND IMPLICATIONS OF KEY FINDINGS
The level of evidence was considered to be "moderate" with "serious" risk of bias according the NTP/OHAT criteria, supporting the need for further well-designed epidemiological research to fill lingering data gaps. Given the complexity of endometriosis and lack of known biomarkers suitable for population-based research, carefully designed observational studies play an important role in better understanding the aetiology of endometriosis, as will evolving mixture modeling approaches capable of handling various environmental chemical exposures. Attention to critical windows of exposure will shed further light on the possible developmental origin of endometriosis. Considering the high economic and societal cost associated with endometriosis, further research on this field is urged.
SYSTEMATIC REVIEW REGISTRATION NUMBER
CRD42018080956.
Topics: Animals; Biomarkers; Endometriosis; Environmental Exposure; Environmental Pollutants; Female; Humans; Pesticides; Polychlorinated Biphenyls
PubMed: 30530163
DOI: 10.1016/j.envint.2018.11.065 -
The Science of the Total Environment Jan 2021Dioxins have been an inconvenience to the Baltic Sea ecosystem for decades. Although the concentrations in the environment and biota have continuously decreased, dioxins...
Dioxins have been an inconvenience to the Baltic Sea ecosystem for decades. Although the concentrations in the environment and biota have continuously decreased, dioxins still pose a risk to human health. The risk and its formation vary in different parts of the Baltic Sea, due to variability in the environmental and societal factors affecting it. This paper presents a systematic literature review and knowledge synthesis about the regional dioxin risk formation in four sub-areas of the Baltic Sea and evaluates, whether systemic approach changes our thinking about the risk and its effective management. We studied the dioxin flux from atmospheric deposition to the Baltic Sea food webs, accumulation to two commercially and culturally important fish species, Baltic herring (Clupea harengus membras) and Baltic salmon (Salmo salar), and further to risk group members of four Baltic countries. Based on 46 studies, we identified 20 quantifiable variables and indexed them for commensurable regional comparison. Spatial differences in dioxin pollution, environmental conditions, food web dynamics, and the following dioxin concentrations in herring and salmon, together with fishing and fish consumption, affect how the final health risk builds up. In the southern Baltic Sea, atmospheric pollution levels are relatively high and environmental processes to decrease bioavailability of dioxins unfavorable, but the growth is fast, which curb the bioaccumulation of dioxins in the biota. In the North, long-range atmospheric pollution is minor compared to South, but the local pollution and slower growth leads to higher bioaccumulation rates. However, based on our results, the most remarkable differences in the dioxin risk formation between the areas arise from the social sphere: the emissions, origin of national catches, and cultural differences in fish consumption. The article suggests that acknowledging spatial characteristics of socio-ecological systems that generate environmental risks may aid to direct local focus in risk management.
Topics: Animals; Baltic States; Dioxins; Ecosystem; Fishes; Humans; Polychlorinated Dibenzodioxins; Water Pollutants, Chemical
PubMed: 33207481
DOI: 10.1016/j.scitotenv.2020.142185 -
Critical Reviews in Toxicology Jul 2019Solid waste incinerators (SWI) emit several pollutants among which polychlorodibenzodioxins and furans (PCDD/Fs), polychlorobiphenyls, metals, monocyclic and polycyclic...
Solid waste incinerators (SWI) emit several pollutants among which polychlorodibenzodioxins and furans (PCDD/Fs), polychlorobiphenyls, metals, monocyclic and polycyclic aromatic hydrocarbons (PAHs). To present a systematic review of peer-reviewed literature on human biological monitoring of exposure and effect following potential exposure to SWI pollutants to bring together evidences and to highlight strengths and deficiencies of the studies conducted so far. Relevant studies on biomonitoring of individuals living near or working at SWIs were selected through three steps: (1) a literature search in the Medline, CAplus, and Embase database; (2) the retrieved abstracts were screened by four independent reviewers; (3) the full text of the relevant papers was read, papers were pooled in studies, and then analyzed to highlight strengths and weaknesses. Studies with the strongest epidemiological design and/or the largest sample size were identified as reference studies. One hundred and thirty-two papers, pooled in 82 studies, were included in the review: 67 on general population, 52 on SWI workers, and 14 on both groups. The most frequently investigated biomarkers were PCDD/Fs in plasma (87). Several studies presented limitations, such as a small samples size, scarce information on confounders, and a poor statistical analysis. Some earlier studies showed an increase of PCDD/Fs, lead, and PAHs in individuals (mainly workers) exposed to emissions from old SWIs; studies from the year 2000 showed no increase of biomarkers or biomarkers within the range of the general population; decreasing trends were observed in prospective studies. Most studies presented methodological pitfalls; reference studies showed no or a limited evidence of the impact of SWI on exposure and effect biomarkers.
Topics: Biological Monitoring; Dibenzofurans; Environmental Exposure; Environmental Pollutants; Humans; Incineration; Polychlorinated Dibenzodioxins; Polycyclic Aromatic Hydrocarbons; Solid Waste
PubMed: 31524034
DOI: 10.1080/10408444.2019.1630362 -
Frontiers in Endocrinology 20212,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a well-known environmental poison that exist in the environment for many years. However, its effect on the male... (Meta-Analysis)
Meta-Analysis
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a well-known environmental poison that exist in the environment for many years. However, its effect on the male reproductive system has not been clearly stated. We conducted a meta-analysis of the effect of TCDD on the male reproductive system of rodents about TCDD. Results showed that that TCDD exposure reduced the testis weight (weighted mean difference [WMD]: -0.035, 95% confidence interval [CI]: -0.046 to -0.025), sperm count (WMD: -35, 95% CI: -42.980 to -27.019), and blood testosterone concentration (WMD: -0.171, 95% CI: -0.269 to -0.073). According to our research results, TCDD can cause damage to the male reproductive system of rodents through direct or indirect exposure. In order to further explore the potential hazards of TCDD to humans, more human-related research needs to be carried out.
Topics: Animals; Data Analysis; Environmental Pollutants; Genitalia, Male; Humans; Male; Men's Health; Models, Animal; Polychlorinated Dibenzodioxins; Rodentia; Semen Analysis; Toxicity Tests
PubMed: 34803904
DOI: 10.3389/fendo.2021.696106 -
Environmental Science & Technology Jun 2021Large quantities of mismanaged plastic waste threaten the health and wellbeing of billions worldwide, particularly in low- and middle-income countries where waste...
Large quantities of mismanaged plastic waste threaten the health and wellbeing of billions worldwide, particularly in low- and middle-income countries where waste management capacity is being outstripped by increasing levels of consumption and plastic waste generation. One of the main self-management strategies adopted by 2 billion people who have no waste collection service, is to burn their discarded plastic in open, uncontrolled fires. While this strategy provides many benefits, including mass and volume reduction, it is a form of plastic pollution that results in the release of chemical substances and particles that may pose serious risks to public health and the environment. We followed adapted PRISMA guidelines to select and review 20 publications that provide evidence on potential harm to human health from open burning plastic waste, arranging evidence into eight groups of substance emissions: brominated flame retardants; phthalates; potentially toxic elements; dioxins and related compounds; bisphenol A; particulate matter; and polycyclic aromatic hydrocarbons. We semiquantitatively assessed 18 hazard-pathway-receptor combination scenarios to provide an indication of the relative harm of these emissions so that they could be ranked, compared and considered in future research agenda. This assessment overwhelmingly indicated a high risk of harm to waste pickers, a large group of 11 million informal entrepreneurs who work closely with waste, delivering a circular economy but often without protective equipment or a structured, safe system of work. Though the risk to human health from open burning emissions is high, this remains a substantially under-researched topic.
Topics: Flame Retardants; Humans; Plastics; Public Health; Recycling; Refuse Disposal
PubMed: 34003007
DOI: 10.1021/acs.est.0c08536 -
Marine Drugs Jun 2019The marine biosphere is a treasure trove of natural bioactive secondary metabolites and the richest source of structurally diverse and unique compounds, such as...
The marine biosphere is a treasure trove of natural bioactive secondary metabolites and the richest source of structurally diverse and unique compounds, such as phlorotannins and halo-compounds, with high therapeutic potential. Eckol is a precursor compound representing the dibenzo-1,4-dioxin class of phlorotannins abundant in the species, which are marine brown algae having a ubiquitous distribution. In search of compounds having biological activity from macro algae during the past three decades, this particular compound has attracted massive attention for its multiple therapeutic properties and health benefits. Although several varieties of marine algae, seaweed, and phlorotannins have already been well scrutinized, eckol deserves a place of its own because of the therapeutic properties it possesses. The relevant information about this particular compound has not yet been collected in one place; therefore, this review focuses on its biological applications, including its potential health benefits and possible applications to restrain diseases leading to good health. The facts compiled in this review could contribute to novel insights into the functions of eckol and potentially enable its use in different uninvestigated fields.
Topics: Animals; Antioxidants; Biological Factors; Dioxins; Humans; Phaeophyceae; Seaweed
PubMed: 31216636
DOI: 10.3390/md17060361 -
Clinical Epigenetics May 2020Assessing long-term health effects from a potentially harmful environment is challenging. Endocrine-disrupting compounds (EDCs) have become omnipresent in our...
Assessing long-term health effects from a potentially harmful environment is challenging. Endocrine-disrupting compounds (EDCs) have become omnipresent in our environment. Individuals may or may not experience clinical health issues from being exposed to the increasing environmental pollution in daily life, but an issue of high concern is that also the non-exposed progeny may encounter consequences of these ancestral exposures. Progress in understanding epigenetic mechanisms opens new perspectives to estimate the risk of man-made EDCs. However, the field of epigenetic toxicology is new and its application in public health or in the understanding of disease etiology is almost non-existent, especially if it concerns future generations. In this review, we investigate the literature on transgenerational inheritance of diseases, published in the past 10 years. We question whether persistent epigenetic changes occur in the male germ line after exposure to synthesized EDCs. Our systematic search led to an inclusion of 43 articles, exploring the effects of commonly used synthetic EDCs, such as plasticizers (phthalates and bisphenol A), pesticides (dichlorodiphenyltrichloroethane, atrazine, vinclozin, methoxychlor), dioxins, and polycyclic aromatic hydrocarbons (PAHs, such as benzo(a)pyrene). Most studies found transgenerational epigenetic effects, often linked to puberty- or adult-onset diseases, such as testicular or prostate abnormalities, metabolic disorders, behavioral anomalies, and tumor development. The affected epigenetic mechanisms included changes in DNA methylation patterns, transcriptome, and expression of DNA methyltransferases. Studies involved experiments in animal models and none were based on human data. In the future, human studies are needed to confirm animal findings. If not transgenerational, at least intergenerational human studies and studies on EDC-induced epigenetic effects on germ cells could help to understand early processes of inheritance. Next, toxicity tests of new chemicals need a more comprehensive approach before they are introduced on the market. We further point to the relevance of epigenetic toxicity tests in regard to public health of the current population but also of future generations. Finally, this review sheds a light on how the interplay of genetics and epigenetics may explain the current knowledge gap on transgenerational inheritance.
Topics: Animals; Atrazine; Benzhydryl Compounds; Benzo(a)pyrene; DDT; Dioxins; Endocrine Disruptors; Epigenesis, Genetic; Male; Mammals; Mice; Paternal Inheritance; Phenols; Phthalic Acids
PubMed: 32398147
DOI: 10.1186/s13148-020-00845-1 -
Emerging Health Threats Journal Apr 2011More than 100 studies have examined whether environmental or occupational exposures of parents affect the sex ratio of their offspring at birth. For this review, we...
More than 100 studies have examined whether environmental or occupational exposures of parents affect the sex ratio of their offspring at birth. For this review, we searched Medline and Web of Science using the terms 'sex ratio at birth' and 'sex ratio and exposure' for all dates, and reviewed bibliographies of relevant studies to find additional articles. This review focuses on exposures that have been the subject of at least four studies including polychlorinated biphenyls (PCBs), dioxins, pesticides, lead and other metals, radiation, boron, and g-forces. For paternal exposures, only dioxins and PCBs were consistently associated with sex ratios higher or lower than the expected 1.06. Dioxins were associated with a decreased proportion of male births, whereas PCBs were associated with an increased proportion of male births. There was limited evidence for a decrease in the proportion of male births after paternal exposure to DBCP, lead, methylmercury, non-ionizing radiation, ionizing radiation treatment for childhood cancer, boron, or g-forces. Few studies have found higher or lower sex ratios associated with maternal exposures. Studies in humans and animals have found a reduction in the number of male births associated with lower male fertility, but the mechanism by which environmental hazards might change the sex ratio has not yet been established.
PubMed: 24149027
DOI: 10.3402/ehtj.v4i0.7109