Dietary exposure to polychlorinated biphenyls and risk of breast, endometrial and ovarian cancer in a prospective cohort

Ambient particulate matter air pollution exposure and ovarian cancer incidence in the USA: An ecological study

OBJECTIVE

To investigate associations between air particulate matter of ≤2.5 μm in diameter (PM2.5 ) and ovarian cancer.

DESIGN

County-level ecological study.

SETTING

Surveillance, epidemiology, and end results from a collection of state-level cancer registries across 744 counties. Data from the Environmental Protection Agency's network for PM2.5 monitoring was used to calculate trailing 5- and 10-year PM2.5 county-level values. County-level data on demographic characteristics were obtained from the American Community Survey.

POPULATION

A total of 98 751 patients with histologically confirmed ovarian cancer as a primary malignancy from 2000 to 2016.

METHODS

Generalised linear regression models were developed to estimate the association between PM2.5 and PM10 levels, over 5- and 10-year periods of exposure, and ovarian cancer risk, after accounting for county-level covariates.

MAIN OUTCOME MEASURES

Risk ratios for associations between ovarian cancer (both overall and specifically epithelial ovarian cancer) and PM2.5 levels.

RESULTS

For the 744 counties included, the average PM2.5 level from 1990 through 2018 was 11.75 μg/m3 (SD = 3.7) and the average PM10 level was 22.7 μg/m3 (SD = 5.7). After adjusting for county-level covariates, the overall annualised ovarian cancer incidence was significantly associated with increases in 5-year PM2.5 (RR = 1.11 per 10 units (μg/m3 ) increase, 95% CI 1.06-1.16). Similarly, when the analysis was limited to epithelial cell tumours and adjusted for county-level covariates there was a significant association with trailing 5-year PM2.5 exposure models (RR = 1.12 per 10 units increase, 95% CI 1.08-1.17). Likewise, 10-year PM2.5 exposure was associated with ovarian cancer overall and with epithelial ovarian cancer.

CONCLUSIONS

Higher county-level ambient PM2.5 levels are associated with 5- and 10-year incidences of ovarian cancer, as measurable in an ecological study.

Total Effective Xenoestrogen Burden in Serum Samples and Risk of Endometrial Cancer in the Spanish Screenwide Case-Control Study

BACKGROUND

Endometrial cancer is a hormone-dependent cancer, and estrogens play a relevant role in its etiology. However, little is known about the effects of environmental pollutants that act as xenoestrogens or that influence estrogenic activity through different pathways.

OBJECTIVE

We aimed to assess the relationship between the combined estrogenic activity of mixtures of xenoestrogens present in serum samples and the risk of endometrial cancer in the Screenwide case-control study.

METHODS

The total effective xenoestrogen burden (TEXB) attributable to organohalogenated compounds (TEXB- α ) and to endogenous hormones and more polar xenoestrogens (TEXB- β ) was assessed in serum from 156 patients with endometrial cancer (cases) and 150 controls by combining chemical extraction and separation by high-performance liquid chromatography with the E-SCREEN bioassay for estrogenicity.

RESULTS

Median TEXB- α and TEXB- β levels for cases (0.30 and 1.25  Eeq pM / mL , respectively) and controls (0.42 and 1.28  Eeq pM / mL , respectively) did not significantly differ (p = 0.653 and 0.933, respectively). An inverted-U risk trend across serum TEXB- α and TEXB- β levels was observed in multivariate adjusted models: Positive associations were observed for the second category of exposure in comparison to the lowest category of exposure [odds ratio  ( OR ) = 2.11 (95% CI: 1.13, 3.94) for TEXB- α , and OR = 3.32 (95% CI: 1.62, 6.81) for TEXB- β ], whereas no significant associations were observed between the third category of exposure and the first [OR = 1.22 (95% CI: 0.64, 2.31) for TEXB- α , and OR = 1.58 (95% CI: 0.75, 3.33) for TEXB- β ]. In mutually adjusted models for TEXB- α and TEXB- β levels, the association of TEXB- α with endometrial cancer risk was attenuated [OR = 1.45 (95% CI: 0.61, 3.47) for the second category of exposure], as well as estimates for TEXB- β (OR = 2.68 ; 95% CI: 1.03, 6.99). Most of the individual halogenated contaminants showed no associations with both TEXB and endometrial cancer.

CONCLUSIONS

We evaluated serum total xenoestrogen burden in relation to endometrial cancer risk and found an inverted-U risk trend across increasing categories of exposure. The use of in vitro bioassays with human samples may lead to a paradigm shift in the way we understand the negative impact of chemical mixtures on human health effects. These results are relevant from a public health perspective and for decision-makers in charge of controlling the production and distribution of chemicals with xenoestrogenic activity. https://doi.org/10.1289/EHP13202.

Dietary omega-3 fatty acids and endometrial cancer risk in the Epidemiology of Endometrial Cancer Consortium: An individual-participant meta-analysis

BACKGROUND

Limited data from prospective studies suggest that higher dietary intake of long-chain omega-3 polyunsaturated fatty acids (LCn3PUFA), which hold anti-inflammatory properties, may reduce endometrial cancer risk; particularly among certain subgroups characterized by body mass and tumor pathology.

MATERIALS AND METHODS

Data from 12 prospective cohort studies participating in the Epidemiology of Endometrial Cancer Consortium were harmonized as nested case-control studies, including 7268 endometrial cancer cases and 26,133 controls. Habitual diet was assessed by food frequency questionnaire, from which fatty acid intakes were estimated. Two-stage individual-participant data mixed effects meta-analysis estimated adjusted odds ratios (OR) and 95% confidence intervals (CI) through logistic regression for associations between study-specific energy-adjusted quartiles of LCn3PUFA and endometrial cancer risk.

RESULTS

Women with the highest versus lowest estimated dietary intakes of docosahexaenoic acid, the most abundant LCn3PUFA in diet, had a 9% increased endometrial cancer risk (Quartile 4 vs. Quartile 1: OR 1.09, 95% CI: 1.01-1.19; P trend = 0.04). Similar elevated risks were observed for the summary measure of total LCn3PUFA (OR 1.07, 95% CI: 0.99-1.16; P trend = 0.06). Stratified by body mass index, higher intakes of LCn3PUFA were associated with 12-19% increased endometrial cancer risk among overweight/obese women and no increased risk among normal-weight women. Higher associations appeared restricted to White women. The results did not differ by cancer grade.

CONCLUSION

Higher dietary intakes of LCn3PUFA are unlikely to reduce endometrial cancer incidence; rather, they may be associated with small to moderate increases in risk in some subgroups of women, particularly overweight/obese women.

Dietary intakes of dioxins and polychlorobiphenyls (PCBs) and breast cancer risk in 9 European countries

BACKGROUND

Dioxins and polychlorobiphenyls (PCBs) are persistent organic pollutants that have demonstrated endocrine disrupting properties. Several of these chemicals are carcinogenic and positive associations have been suggested with breast cancer risk. In general population, diet represents the main source of exposure.

METHODS

Associations between dietary intake of 17 dioxins and 35 PCBs and breast cancer were evaluated in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort from nine European countries using multivariable Cox regressions. The present study included 318,607 women (mean ± SD age: 50.7 ± 9.7) with 13,241 incident invasive breast cancers and a median follow-up of 14.9 years (IQR = 13.5-16.4). Dietary intake of dioxins and PCBs was assessed combining EPIC food consumption data with food contamination data provided by the European Food Safety Authority.

RESULTS

Exposure to dioxins, dioxins + Dioxin-Like-PCBs, Dioxin-Like-PCBs (DL-PCBs), and Non-Dioxin-Like-PCBs (NDL-PCBs) estimated from reported dietary intakes were not associated with breast cancer incidence, with the following hazard ratios (HRs) and 95% confidence intervals for an increment of 1 SD: HRdioxins = 1.00 (0.98 to 1.02), HRdioxins+DL-PCB = 1.01 (0.98 to 1.03), HRDL-PCB = 1.01 (0.98 to 1.03), and HRNDL-PCB = 1.01 (0.99 to 1.03). Results remained unchanged when analyzing intakes as quintile groups, as well as when analyses were run separately per country, or separating breast cancer cases based on estrogen receptor status or after further adjustments on main contributing food groups to PCBs and dioxins intake and nutritional factors.

CONCLUSIONS

This large European prospective study does not support the hypothesis of an association between dietary intake of dioxins and PCBs and breast cancer risk.

Endocrine Disruptors and Endometrial Cancer: Molecular Mechanisms of Action and Clinical Implications, a Systematic Review

It has been widely demonstrated that endocrine disruptors play a central role in various physiopathological processes of human health. In the literature, various carcinogenic processes have been associated with endocrine disruptors. A review of the molecular mechanisms underlying the interaction between endocrine disruptors and the endometrial cancer has been poorly developed. A systematic review was performed using PubMed^®/MEDLINE. A total of 25 in vivo and in vitro works were selected. Numerous endocrine disruptors were analyzed. The most relevant results showed how Bisphenol A (BPA) interacts with the carcinogenesis process on several levels. It has been demonstrated how BPA can interact with hormonal receptors and with different transcription proliferative and antiproliferative factors. Furthermore, the effect of Polycyclic aromatic hydrocarbons on Aryl hydrocarbon receptors was investigated, and the role of flame retardants in promoting proliferation and metastasis was confirmed. The results obtained demonstrate how the mechanisms of action of endocrine disruptors are manifold in the pathophysiology of endometrial cancer, acting on different levels of the cancerogenesis process.

Dose-dependent toxicological effects in rats following a 90-day dietary exposure to PCB-156 include retinoid disruption

The toxicity of PCB-156 (2,3,3',4,4',5-hexachlorobiphenyl) was investigated in rats following subchronic dietary exposure. Groups of 10 male and female Sprague-Dawley rats were administered PCB-156 in the diet at 0, 0.01, 0.1, 1 or 10 ppm for 90 days. Dose-dependent increases were detected for the liver, lung and kidney weights, as well as for the liver EROD, PROD and UDPGT enzyme activities and liver uroporphyrin concentration. Dose-dependent decreases were observed in final body weight, body weight gain, and thymus weight. Apolar retinoid concentrations were decreased in the liver and lungs and increased in the kidneys. Histopathological examination of the liver, thyroid, and thymus showed mild to moderate dose-related changes. A LOAEL of 0.01 ppm was established, based on reduced apolar liver retinoid concentration. Benchmark dose-modelling corroborated the sensitivity of liver retinoid endpoints. The lower confidence limits (BMDL) for a 5% decrease in apolar liver retinoid concentrations were 0.0009 and 0.0007 ppm, respectively, in males and females, corresponding to a daily dose of 0.06 μg PCB-156 per kg body weight. Organizing dose-response data for the individual hepatic endpoints along the PCB-156 dosing scale revealed a sequence of events compatible with a causal link between depletion of apolar retinoids and the other liver biochemistry and pathology findings. Taken together, data suggest that the retinoid endpoints should be further evaluated for a causal relationship to PCB-induced liver toxicity and that retinoid system endpoints are identified and characterized to support health risk assessment in the emerging research fields of endocrine disruption and mixture toxicology.

Adipose Tissue Redox Microenvironment as a Potential Link between Persistent Organic Pollutants and the 16-Year Incidence of Non-hormone-Dependent Cancer

We aimed to assess the relationships among the adipose tissue's (AT) oxidative microenvironment, in situ accumulated persistent organic pollutant (POP) concentrations, and cancer development. POP and oxidative stress levels were quantified in AT samples from 382 adults recruited within the GraMo cohort (2003-2004) in Granada (Spain). The 16-year cancer incidence was ascertained by reviewing health/administrative databases. Cox-regression models and mediation analyses were performed. The enzymes superoxide dismutase (SOD) and glutathione reductase (GRd) were positively associated with the risk of non-hormone-dependent (NHD) cancer [adjusted hazard ratio (HR) 1.76; 95% confidence interval (CI): 1.17, 2.64 and HR 2.35; 95% CI: 1.41, 3.94, respectively]. After adjustment for covariates, polychlorinated biphenyl-138 (PCB-138) (HR 1.78; 95% CI: 1.03, 3.09), β-hexachlorocyclohexane (β-HCH) (HR 1.70; 95% CI: 1.09, 2.64), and hexachlorobenzene (HR 1.54; 95% CI: 1.02, 2.33) were also positively associated with the risk of NHD cancer. Although confidence intervals included the null value, probably because of the modest number of cancer cases, we observed a potential mediation effect of SOD and GRd on the associations between β-HCH and the risk of NHD tumors (percent mediated = 33 and 47%, respectively). Our results highlight the relevance of human AT's oxidative microenvironment as a predictor of future cancer risk as well as its potential mediating role on POP-related carcinogenesis. Given their novelty, these findings should be interpreted with caution and confirmed in future studies.

A cross-sectional study of the association between perfluorinated chemical exposure and cancers related to deregulation of estrogen receptors

BACKGROUND

Environmental exposures acting through different mechanisms have been linked with a number of cancers. Perfluoroalkyl chemicals (PFCs) are endocrine disrupting chemicals affecting estrogen homeostasis.

OBJECTIVES

We examined the association between PFCs and a group of estrogen related cancers and explored if increased non-occupational exposure was associated with increased odds of developing these cancers. We also explored which of these chemical exposures was more correlated with each cancer.

METHODS

Using data from the National Health and Nutrition Examination Survey (NHANES), we selected participants ≥ 20 years of age. Our outcome variable was presence or absence of breast, prostate, ovarian and uterine cancer (yes/no); our exposure variables were serum PFCs. Logistic regression models were used in investigating the association between PFCs and cancer types and between quartiles of PFCs exposure concentrations and presence or absence of cancer while adjusting for covariates. Discriminant analysis was used to assess the correlation between individual PFCs compounds and individual cancer types.

RESULTS

PFCs were associated with increased odds of ovarian cancer; PFOA: 1.02(1.01, 1.02), PFOS: 1.01 (1.012, 1.013), PFHS 1.031 (1.030, 1.033), PFDE: 1.29(1.27, 1.30) and increased odds of breast cancer; PFOA: 1.089(1.089, 1.09), PFOS: 1.011(1.011, 1.011), PFNA: 1.031(1.030, 1.033), PFHS: 1.02 (1.02, 1.02), PFDE: 1.19(1.18, 1.19). PFCs were not associated with increased odds of prostate or uterine cancers. Comparing the odds in quartile 4 to quartile 1 for ovarian cancer, PFOA: 1.77(1.75,1.79), PFOS: 2.25(2.22, 2.28), PFHS: 1.86(1.84, 1.88), PFDE: 2.11(2.09, 2.14). For breast cancer, PFOA: 2.30(2.28, 2.31), PFOS: 1.47(1.46, 1.48), PFNA: 1.04(1.03, 1.05), PFHS:7.07(6.97,7.17), PFDE: 1.38(1.37, 1.39). PFOA was more correlated with breast cancer (0.7) and PFHS was more correlated with ovarian cancer (0.9).

DISCUSSION

PFCs were associated with increased odds of ovarian and breast cancers with a positive dose-response relationship. PFOA was more correlated with breast cancer and PFHS more with ovarian cancer.

Endocrine disrupting chemicals and breast cancer: a systematic review of epidemiological studies

BACKGROUND

Endocrine-disrupting compounds (EDCs) are ubiquitous substances that are found in our everyday lives, including pesticides, plasticizers, pharmaceutical agents, personal care products, and also in food products and food packaging. Increasing epidemiological evidence suggest that EDCs may affect the development or progression of breast cancer and consequently lead to lifelong harmful health consequences, especially when exposure occurs during early life in humans. Yet so far no appraisal of the available evidence has been conducted on this topic.

OBJECTIVE

To systematically review all the available epidemiological studies about the association of the levels of environmental exposures of EDCs with breast cancer risk.

METHODS

The search was performed in accordance with the PRISMA guidelines. We retrieved articles from PubMed (MEDLINE) until 10 March 2021. The key words used in this research were: "Endocrine disruptor(s)" OR "Endocrine disrupting chemical(s)" OR any of the EDCs mentioned below AND "Breast cancer" to locate all relevant articles published. We included only cohort studies and case-control studies. All relevant articles were accessed in full text and were evaluated and summarized in tables.

RESULTS

We identified 131 studies that met the search criteria and were included in this systematic review. EDCs reviewed herein included pesticides (e.g. p,p'-dichlorodiphenyltrichloroethane (DDT), p,p'-dichlorodiphenyldichloroethylene (DDE), atrazine, 2,3,7,8-tetrachloridibenzo-p-dioxin (TCDD or dioxin)), synthetic chemicals (e.g. bisphenol A (BPA), phthalates, per- and polyfluoroalkyl substances (PFAS), parabens, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), contraceptive pills), phytoestrogens (e.g. genistein, resveratrol), and certain mycotoxins (e.g. zearalenone). Most studies assessed environmental EDCs exposure via biomarker measurements.

CONCLUSION

We identified certain EDC exposures could potentially elevate the risk of breast cancer. As majority of EDCs are highly persistent in the environment and bio-accumulative, it is essential to assess the long-term impacts of EDC exposures, especially multi-generational and transgenerational. Also, since food is often a major route of exposure to EDCs, well-designed exposure assessments of potential EDCs in food and food packing are necessary and their potential link to breast cancer development need to be carefully evaluated for subsequent EDC policy making and regulations.

Long-term atmospheric exposure to PCB153 and breast cancer risk in a case-control study nested in the French E3N cohort from 1990 to 2011

BACKGROUND

Although the genetic and hormonal risk factors of breast cancer are well identified, they cannot fully explain the occurrence of all cases. Epidemiological and experimental studies have suggested that exposure to environmental pollutants, especially those with potential estrogenic properties, as polychlorinated biphenyls (PCBs) may have a role in breast cancer development. Being the most abundantly detected in human tissues and in the environment, congener 153 (PCB153) is widely used in epidemiological studies as indicator for total PCBs exposure.

OBJECTIVES

We aimed to estimate the association between cumulative atmospheric exposure to PCB153 and breast cancer risk.

METHODS

We conducted a case-control study of 5222 cases and 5222 matched controls nested within the French E3N cohort from 1990 to 2011. Annual atmospheric PCB153 concentrations were simulated with the deterministic chemistry-transport model (CHIMERE) and were assigned to women using their geocoded residential history. Their cumulative PCB153 exposure was calculated for each woman from their cohort inclusion to their index date. Breast cancer odds ratios (ORs) associated with cumulative PCB153 exposure and their 95% confidence intervals (95% CIs) were estimated using multivariate conditional logistic regression models.

RESULTS

Overall, our results showed a statistically significant linear increase in breast cancer risk related to cumulative atmospheric exposure to PCB153 as a continuous variable (adjusted OR = 1.19; 95% CI: 1.08-1.31, for an increment of one standard deviation among controls (55 pg/m³)). Among women who became postmenopausal during follow-up, the association remained statistically significant (adjusted OR = 1.23; 95% CI: 1.09-1.39). In analyses by hormone receptors status, the positive association remained significant only for ER-positive breast cancer (adjusted OR = 1.18; 95% CI: 1.05-1.33).

DISCUSSION

This study is the first to have estimated the impact of atmospheric exposure to PCB153 on breast cancer risk. Our results showed a statistically significant increase in breast cancer risk, which may be limited to ER-positive breast cancer. These results warrant confirmation in further independent studies but raise the possibility that exposure to PCB153 increase breast cancer risk.

Endocrine Disruptors Acting on Estrogen and Androgen Pathways Cause Reproductive Disorders through Multiple Mechanisms: A Review

Increasing contamination of the environment by toxic compounds such as endocrine disrupting chemicals (EDCs) is one of the major causes of reproductive defects in both sexes. Estrogen/androgen pathways are of utmost importance in gonadal development, determination of secondary sex characteristics and gametogenesis. Most of the EDCs mediate their action through respective receptors and/or downstream signaling. The purpose of this review is to highlight the mechanism by which EDCs can trigger antagonistic or agonistic response, acting through estrogen/androgen receptors causing reproductive defects that lead to infertility. In vitro, in vivo and in silico studies focusing on the impact of EDCs on estrogen/androgen pathways and related proteins published in the last decade were considered for the review. PUBMED and PUBCHEM were used for literature search. EDCs can bind to estrogen receptors (ERα and ERβ) and androgen receptors or activate alternative receptors such as G protein-coupled receptors (GPCR), GPR30, estrogen-related receptor (ERRγ) to activate estrogen signaling via downstream kinases. Bisphenol A, dichlorodiphenyltrichloroethane, dichlorodiphenyldichloroethylene, polychlorinated biphenyls and phthalates are major toxicants that interfere with the normal estrogen/androgen pathways leading to infertility in both sexes through many ways, including DNA damage in spermatozoids, altered methylation pattern, histone modifications and miRNA expression.

Mortality in Yusho patients exposed to polychlorinated biphenyls and polychlorinated dibenzofurans: a 50-year retrospective cohort study

BACKGROUND

In 1968, the Yusho incident resulted in accidental exposure to polychlorinated biphenyls (PCBs), polychlorinated dibenzofurans (PCDFs), and related compounds in Japan. This study updated the risk of mortality in Yusho patients.

METHODS

We obtained updated cohort data for all Yusho patients for the period 1968-2017. We calculated standardized mortality ratios (SMRs) for all-cause and cause-specific mortality over a 50-year follow-up period compared with the general population in Japan.

RESULTS

A total of 1664 Yusho patients with 63,566 person-years of follow up were included in the analysis. Among males, excess mortality was observed for all cancers (SMR: 1.22, 95% confidence interval [CI]: 1.02 to 1.45) and lung cancer (SMR: 1.59, 95% CI: 1.12 to 2.19). Among females, increased mortality was observed for liver cancer (SMR: 2.05, 95% CI: 1.02 to 3.67). No significant increase was seen in non-cancer-related mortality compared with the general population.

CONCLUSIONS

Carcinogenic risk in humans after exposure to PCBs and PCDFs remains higher among Yusho patients. Our findings suggest the importance of care engagement and optimum management to deal with the burden of Yusho disease.

Association between dietary intake and risk of ovarian cancer: a systematic review and meta-analysis

PURPOSE

It is unclear how dietary intake influences the ovarian cancer. The present paper sets out to systematically review and meta-analyze research on dietary intake to identify cases having high- or low-risk ovarian cancer.

METHODS

Scopus, PubMed, and Wiley Online Libraries were searched up to the date November 24, 2019. Two reviewers were requested to independently extract study characteristics and to assess the bias and applicability risks with reference to the study inclusion criteria. Meta-analyses were performed to specify the relationship between dietary intake and the risk of ovarian cancer identifying 97 cohort studies.

RESULTS

No significant association was found between dietary intake and risk of ovarian cancer. The results of subgroup analyses indicated that green leafy vegetables (RR = 0.91, 95%, 0.85-0.98), allium vegetables (RR = 0.79, 95% CI 0.64-0.96), fiber (RR = 0.89, 95% CI 0.81-0.98), flavonoids (RR = 0.83, 95% CI 0.78-0.89) and green tea (RR = 0.61, 95% CI 0.49-0.76) intake could significantly reduce ovarian cancer risk. Total fat (RR = 1.10, 95% CI 1.02-1.18), saturated fat (RR = 1.11, 95% CI 1.01-1.22), saturated fatty acid (RR = 1.19, 95% CI 1.04-1.36), cholesterol (RR = 1.13, 95% CI 1.04-1.22) and retinol (RR = 1.14, 95% CI 1.00-1.30) intake could significantly increase ovarian cancer risk. In addition, acrylamide, nitrate, water disinfectants and polychlorinated biphenyls were significantly associated with an increased risk of ovarian cancer.

CONCLUSION

These results could support recommendations to green leafy vegetables, allium vegetables, fiber, flavonoids and green tea intake for ovarian cancer prevention.

PCB levels in adipose tissue of dogs from illegal dumping sites in Campania region (Italy)

The aim of the study is to investigate the potential relationship between exposure to PCBs and cancer. In doing so we relied on a sample of dogs coming from a peculiar area of the Campania region (Italy), that has been suffering for illegal waste dumping and open air burning of plastic waste for many years. The latter determined the release of organic and inorganic pollutants, such as the PCBs. By comparing dogs with cancer and healthy dogs, we found much higher PCB concentrations in the former, with a significant difference (p < 0.05) for the non-indicator ∑10NDL-PCB and the DL-PCBs. A regression analysis, controlling for three potentially confounding factors, that are sex, age and weight, confirmed the higher ∑10NDL-PCB concentration in dogs with cancer. Hence, our evidence suggests a potential health hazard for animals and likewise people living in a risky area due to the presence of environmental organic pollutants.

Cardiovascular and cancer mortality in relation to dietary polychlorinated biphenyls and marine polyunsaturated fatty acids: a nutritional-toxicological aspect of fish consumption

BACKGROUND

Co-exposure to environmental contaminants present in fish could mitigate the beneficial effects of fish consumption and possibly explain the lack of association observed for mortality in some geographical regions.

OBJECTIVE

To assess the independent associations of dietary exposure to polychlorinated biphenyls (PCBs) and long-chain omega-3 fish fatty acids intake with cardiovascular and cancer mortality.

METHODS

We used the prospective population-based Swedish Mammography Cohort and the Cohort of Swedish Men comprising 32 952 women and 36 545 men, free from cancer, cardiovascular disease and diabetes at baseline in 1998. Validated estimates of dietary PCBs and long-chain omega-3 fish fatty acids [i.e. eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] intake were obtained via a food frequency questionnaire at baseline. Information on death was ascertained through register linkage.

RESULTS

During a mean follow-up of 15.5 years, we ascertained 16 776 deaths. We observed for cardiovascular mortality, comparing extreme quintiles in multivariable models mutually adjusted for PCBs and EPA-DHA, dose-dependent associations for dietary PCB exposure, hazard ratio (HR) 1.31 (CI 95%: 1.08 to 1.57; P-trend 0.005) and for dietary EPA-DHA intake, HR 0.79 (CI 95%: 0.66 to 0.95; P-trend 0.041). For cancer mortality, no clear associations were discerned.

CONCLUSION

The beneficial effect of fish consumption on the cardiovascular system seems compromised by co-exposure to PCBs - one likely explanation for the inconsistent associations observed between fish consumption and mortality.

Exposure to persistent organic pollutants: impact on women's health

This literature review focuses on the causal relationship between persistent organic pollutants (POPs) exposure and women's health disorders, particularly cancer, cardio-metabolic events and reproductive health. Progressive industrialization has resulted in the production of a multitude of chemicals that are released into the environment on a daily basis. Environmental chemicals or pollutants are not only hazardous to our ecosystem but also lead to various health problems that affect the human population worldwide irrespective of gender, race or age. However, most environmental health studies that have been conducted, until recently, were exclusively biased with regard to sex and gender, beginning with exposure studies that were reported mostly in male, occupational workers and animal studies being carried out mostly in male rodent models. Health-related issues pertaining to women of all age groups have not been studied thoroughly and rather disregarded in most aspects of basic health science research and it is therefore pertinent that we address these limitations in environmental health. The review also addresses studies looking at the associations between health outcomes and exposures to POPs, particularly, polychlorinated biphenyls (PCBs), dioxins and pesticides, reported in cohort studies while accounting for gender differences. Considering that current levels of POPs in women can also impact future generations, informative guidelines related to dietary patterns and exposure history are needed for women of reproductive age. Additionally, occupational cohorts of highly exposed women worldwide, such as women working in manufacturing plants and female pesticide applicators are required to gather more information on population susceptibility and disease pathology.

Utilizing ion mobility spectrometry and mass spectrometry for the analysis of polycyclic aromatic hydrocarbons, polychlorinated biphenyls, polybrominated diphenyl ethers and their metabolites

Polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) are persistent environmental pollutants originating from incomplete combustion of organic materials and synthetic sources. PAHs, PCBs, and PBDEs have all been shown to have a significant effect on human health with correlations to cancer and other diseases. Therefore, measuring the presence of these xenobiotics in the environment and human body is imperative for assessing their health risks. To date, their analyses require both gas chromatography and liquid chromatography separations in conjunction with mass spectrometry measurements for detection of both the parent molecules and their hydroxylated metabolites, making their studies extremely time consuming. In this work, we characterized PAHs, PCBs, PBDEs and their hydroxylated metabolites using ion mobility spectrometry coupled with mass spectrometry (IMS-MS) and in combination with different ionization methods including electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI). The collision cross section and m/z trend lines derived from the IMS-MS analyses displayed distinct trends for each molecule type. Additionally, the rapid isomeric and molecular separations possible with IMS-MS showed great promise for quickly distinguishing the parent and metabolized PAH, PCB, and PDBE molecules in complex environmental and biological samples.