Internal exposure to organochlorine pollutants and cadmium and self-reported health status: a prospective study

Physical exercise and persistent organic pollutants

Exposure to the legacy and emerging persistent organic pollutants (POPs) incessantly has become an important threat to individual health, which is closely related to neurodevelopment, endocrine and cardiovascular homeostasis. Exercise, on the other hand, has been consistently shown to improve physical fitness. Whereas associations between traditional air pollutants, exercise and lung function have been thoroughly reviewed, reviews on associations between persistent organic pollutants and exercise are scarce. Hence, a literature review focused on exercise, exposure to POPs, and health risk assessment was performed for studies published from 2004 to 2022. The purpose of this review is to provide an overview of exposure pathways and levels of POPs during exercise, as well as the impact of exercise on health concerns attributable to the redistribution, metabolism, and excretion of POPs in vivo. Therein lies a broader array of exercise benefits, including insulin sensitizing, mitochondrial DNA repair, lipid metabolism and intestinal microecological balance. Physical exercise is conducive to reduce POPs body burden and resistant to health hazards of POPs generally. Besides, individual lipid metabolism condition is a critical factor in evaluating potential link in exercise, POPs and health effects.

The diabetogenic effects of pesticides: Evidence based on epidemiological and toxicological studies

While the use of pesticides has improved grain productivity and controlled vector-borne diseases, the widespread use of pesticides has resulted in ubiquitous environmental residues that pose health risks to humans. A number of studies have linked pesticide exposure to diabetes and glucose dyshomeostasis. This article reviews the occurrence of pesticides in the environment and human exposure, the associations between pesticide exposures and diabetes based on epidemiological investigations, as well as the diabetogenic effects of pesticides based on the data from in vivo and in vitro studies. The potential mechanisms by which pesticides disrupt glucose homeostasis include induction of lipotoxicity, oxidative stress, inflammation, acetylcholine accumulation, and gut microbiota dysbiosis. The gaps between laboratory toxicology research and epidemiological studies lead to an urgent research need on the diabetogenic effects of herbicides and current-use insecticides, low-dose pesticide exposure research, the diabetogenic effects of pesticides in children, and assessment of toxicity and risks of combined exposure to multiple pesticides with other chemicals.

The association between environmental cadmium exposure, blood pressure, and hypertension: a systematic review and meta-analysis

We performed a systematic and meta-analysis study to find the association between cadmium (Cd) exposure and blood pressure (BP)/hypertension (HTN) in exposed general populations. We searched main databases for literature published between year 2000 and April 15, 2021. Quality assessment was performed with the Joanna Briggs Institute (JBI) critical appraisal tools. Heterogeneity between studies was determined by I-squared (I²) statistic. The random effects model was used to determine the association between blood and urine Cd levels with hypertension. The overall standard differences in mean for Cd level in hypertensive and control groups were 3.34, 1.79, and 8.09 based on samples from blood, urine, and hair, respectively. The overall standard differences in mean for Cd level in the low and high exposure groups were - 0.795 and - 1.036 based on blood and urinary samples, respectively. Our findings indicate a positive relationship between blood and hair Cd levels and hypertension. We also found that hair is the optimal biological sample to find the relationship between Cd exposure and hypertension for both genders. However, more studies are needed to confirm these findings.

Persistent organic pollutants and β-cell toxicity: a comprehensive review

Persistent organic pollutants (POPs) are a diverse family of contaminants that show widespread global dispersion and bioaccumulation. Humans are continuously exposed to POPs through diet, air particles, and household and commercial products; POPs are consistently detected in human tissues, including the pancreas. Epidemiological studies show a modest but consistent correlation between exposure to POPs and increased diabetes risk. The goal of this review is to provide an overview of epidemiological evidence and an in-depth evaluation of the in vivo and in vitro evidence that POPs cause β-cell toxicity. We review evidence for six classes of POPs: dioxins, polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), organophosphate pesticides (OPPs), flame retardants, and per- and polyfluoroalkyl substances (PFAS). The available data provide convincing evidence implicating POPs as a contributing factor driving impaired glucose homeostasis, β-cell dysfunction, and altered metabolic and oxidative stress pathways in islets. These findings support epidemiological data showing that POPs increase diabetes risk and emphasize the need to consider the endocrine pancreas in toxicity assessments. Our review also highlights significant gaps in the literature assessing islet-specific endpoints after both in vivo and in vitro POP exposure. In addition, most rodent studies do not consider the impact of biological sex or secondary metabolic stressors in mediating the effects of POPs on glucose homeostasis and β-cell function. We discuss key gaps and limitations that should be assessed in future studies.

Air Pollution Control and Public Health Risk Perception: Evidence from the Perspectives of Signal and Implementation Effects

The main purposes of government environmental policy include improving the objective natural environment as well as reducing the health risk of the public. A majority of studies have tested the means of achieving the first goal. In this paper, we aimed to gather empirical evidence pertaining to the realization of the second goal by drawing on a quasi-natural experiment that was conducted based on the “Action Plan on Air Pollution Prevention and Control” issued in 2013 (AP2013). The research data came from the tracking data of 17,766 individuals from 112 prefecture-level cities of China in 2012 and 2014. Through ordinal logistic regression and DID analysis, a causal relationship between the AP2013 policy and public health risk perceptions was verified, indicating that this policy can significantly decrease public health risk perceptions. By constructing different subsamples, an inverted U-shaped relationship between the causal effect and the length of the policy implementation window was established, which demonstrated the short-term signal effect and long-term implementation effect of this policy. The conclusions can help with the communication and implementation of a government’s policy.

Exposure to the pesticide DDT and risk of diabetes and hypertension: Systematic review and meta-analysis of prospective studies

BACKGROUND

Experimental evidence suggests that p,p'-DDE might be involved in the development of diabetes and hypertension (HTN); however, the evidence in humans is inconclusive.

OBJECTIVE

To summarize the epidemiological evidence for the association of p,p'-DDT exposure and its breakdown products with the risk of diabetes and HTN from prospective studies.

METHODS

We performed a systematic review and meta-analysis based on the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. Eligible studies (prospective) were search in PubMed, Web of Science, EBSCO, and SciELO databases (July 11, 2020). Different search algorithms were used for diabetes and HTN. Pooled odds ratios (ORs) were estimated from meta-analysis with random effects for each exposure and outcome.

RESULTS

A total of 23 prospective studies were included in this review, 16 assessed diabetes and seven HTN; very few measured p,p'-DDT. Exposure to p,p'-DDE was associated with a slightly increased risk of type 2 diabetes (T2D) (pooled OR = 1.44; 95%CI: 1.00, 2.07; p = 0.049) and HTN (pooled OR = 1.21; 95%CI: 1.07, 1.38). Dose-response meta-analysis suggested a non-linear relation between p,p'-DDE and T2D. Exposure to p,p'-DDE was not associated with gestational diabetes (pooled OR = 1.01; 95%CI: 0.94, 1.09); similarly, p,p'-DDT was not associated with T2D (pooled OR = 1.03; 95%CI: 0.79, 1.35).

CONCLUSIONS

Evidence from prospective studies suggests that exposure to p,p'-DDE, the main breakdown product of p,p'-DDT, might increase the risk of developing T2D; such increase may be apparent only at low levels. Exposure to p,p'-DDE may also increase the risk of having HTN; however, further evidence is required.

Levels of metals and persistent organic pollutants in traditional foods consumed by First Nations living on-reserve in Canada

Objectives

First Nations may have a higher risk of contaminant exposure from the consumption of traditional foods. The objective of this study was to measure concentrations of metals and organochlorines in traditional foods commonly consumed by First Nations in Canada and estimate the risk from dietary exposure.

Methods

Data were collected from the participatory First Nations Food, Nutrition and Environment Study (2008–2018). Traditional food samples were collected by community members and concentrations of metals and organochlorines were measured. The population-weighted mean daily contaminant intake from traditional food items was estimated. Hazard quotients (HQs) were calculated by dividing contaminant intake with the toxicological reference values (TRVs).

Results

A total of 2061 food samples (different parts and organs) from 221 species were collected. The highest concentrations of cadmium were found in the kidneys of land mammals: moose kidney was the most significant contributor to intake. The meat of land mammals and birds had the highest lead concentrations and were the most significant contributors to intake. Arsenic was highest in seaweed, and prawn was the most significant contributor. Mercury and methyl mercury were highest in harp seal meat, with walleye/pickerel contributing most to intake. Harp seal meat also had the highest p,p′-DDE and PCB concentrations, and ooligan grease and salmon were the most significant contributors to intake. The percentage of adults eating traditional food who exceeded the TRVs was 1.9% for cadmium, 3.7% for lead, 13.6% for arsenic, 0.7% for mercury, and 0% for p,p′-DDE and PCBs. All median HQs, and most 95th percentile HQs, were less than 1.

Conclusion

These results can be used as a baseline of contaminant levels and exposure in traditional foods for future monitoring programs and to support risk assessment programs.

Supplementary Information

The online version contains supplementary material available at 10.17269/s41997-021-00495-7.

PCB118 Induces Inflammation of Islet Beta Cells via Activating ROS-NLRP3 Inflammasome Signaling

Background

Diabetes mellitus is a clinical syndrome caused by genetic and environmental factors. Growing evidence suggests that exposure to environmental endocrine disruptors and activation of NLRP3 inflammasome signaling play a vital role in diabetes. However, it is unclear how PCB118, a common environmental endocrine disruptor, contributes to the incidence of diabetes, and its specific mechanism of action is unknown. In this study, we explored whether ROS-induced NLRP3 inflammasome priming and activation were related to PCB118 exposure in mouse islet β-TC-6 cells and the mechanisms of diabetes.

Methods

Mouse islet β-TC-6 cells were cultured with PCB118 as a stimulating factor and ROS inhibitor N-acetyl cysteine (NAC) as an intervention. Cellular toxicity due to PCB118 was detected using the Cell Counting Kit-8; ROS was measured using DCFH-DA; the expressions of NLRP3, procaspase-1, caspase-1, pro-IL-1β, and IL-1β protein were detected by western blot; and IL-6, IL-18, and C-C chemokine ligand 2 (CCL-2) were measured by ELISA.

Results

PCB118 caused significant toxicity to the cells when the stimulation concentration was equal to or greater than 80 nmol/L at 72 hours (p < 0.05) and increased the levels of ROS, NLRP3, caspase-1, IL-1β, IL-6, IL-18, and CCL-2 (p < 0.05); the expressions of procaspase-1 and pro-IL-1β were downregulated in a dose-dependent manner after PCB118 exposure (p < 0.05), which was prevented by pretreatment with NAC (p < 0.05).

Conclusions

PCB118 can activate NLRP3 inflammasome signaling in islet beta cells via the oxidative stress pathway and cause inflammation in islet beta cells. It suggests that environmental endocrine disruptors play an important role in the inflammation of islet beta cells and may contribute to the development of diabetes through NLRP3 inflammatory signaling.

Urine Cadmium as a Risk Factor for Osteoporosis and Osteopenia: A Meta-Analysis

Background: As society ages, the incidence of osteoporosis increases. In several studies, cadmium (Cd) is thought to be related to osteoporosis. However, there are conflicting reports about the relationship between Cd and the risk of osteoporosis and osteopenia. Therefore, the purpose of this meta-analysis was to explore the relationship between Cd and osteoporosis and osteopenia.

Methods: Through a review of the literature, articles published in PubMed as of December 2020 were identified and the references of related publications and reviews were reviewed. Ultimately, 17 eligible articles were selected to determine the relationship between blood and urine Cd concentrations for the risk of osteoporosis or osteopenia. In this study, we performed a classification analysis, heterogeneity test, subgroup analysis, and evaluated publication bias.

Results: A total of 17 studies were included, including seven on blood Cd and 10 on urine Cd. By combining the odds ratio (OR) and 95% confidence interval (CI) for the lowest and highest categories, the odds ratio of blood Cd concentration that increased the risk of osteoporosis or osteopenia was OR 1.21 (95% CI: 0.84–1.58) and that of urine Cd concentration that increased the risk of osteoporosis or osteopenia was OR 1.80 (95% CI: 1.42–2.18), and the results of the subgroup analysis were also consistent.

Conclusions: Our research indicates that while urine cadmium (Cd) concentration may be related to increased risk of osteoporosis and osteopenia, blood Cd concentration may not. Therefore, compared to blood Cd concentration, urine Cd concentration may be more reliable as a risk factor for osteoporosis and osteopenia. This result should be interpreted with caution. Currently. research on the relationship between Cd concentration and osteoporosis and osteopenia is limited, thus, further large, high-quality prospective studies are required to elucidate the relationship between Cd concentration and osteoporosis and osteopenia.

An updated systematic review on the association between Cd exposure, blood pressure and hypertension

BACKGROUND

Since the first report by Perry et al. (1955), most studies affirmed the hypertensive effects of cadmium (Cd) in humans. Nonetheless, conclusions between studies remain inconsistent.

OBJECTIVE

The aim of this study was to reevaluate the evidence for a potential relationship between Cd exposure and altered blood pressure and/or hypertension, focusing on studies published between January 2010 and March 2020.

METHODS

We reviewed all observational studies from database searches (PubMed and SCOPUS) on Cd exposure and blood pressure or hypertension. We extracted information from studies that provided sufficient data on population characteristics, smoking status, exposure, outcomes, and design.

RESULTS

Thirty-eight studies met our inclusion criteria; of those, twenty-nine were cross sectional, three case control, five cohort and one interventional study. Blood or urinary Cd levels were the most commonly used biomarkers.

CONCLUSIONS

A positive association between blood Cd levels and blood pressure and/or hypertension was identified in numerous studies at different settings. Limited number of representative population-based studies of never-smokers was observed, which may have confounded our conclusions. The association between urinary Cd and blood pressure and/or hypertension remains uncertain due to conflicting results, including inverse relationships with lack of strong mechanistic support. We point to the urgent need for additional longitudinal studies to confirm our findings.

Exposure to heavy metals and the risk of osteopenia or osteoporosis: a systematic review and meta-analysis

The relationship between heavy metal exposure and risk of osteopenia or osteoporosis has biological plausibility, yet it remains inconclusive; therefore, we conducted a systematic review and meta-analysis to evaluate the associations between exposure to heavy metals (i.e., cadmium, lead, and mercury) and the risk of osteopenia or osteoporosis. Databases of MEDLINE, Embase, Scopus, and Web of Science were searched through November 2019, to identify studies that evaluated the relationship between exposure to cadmium, lead, and mercury and risk of osteopenia or osteoporosis in adults. Fourteen eligible studies were included. Effect sizes expressed as pooled odds ratios (OR) and 95% confidence intervals (CI) were estimated using weighted random-effect models. Exposure to cadmium (OR = 1.35; 95% CI: 1.17 to 1.56; P ≤ 0.001) and lead (OR = 1.15; 95% CI: 1.00 to 1.32; P = 0.05) was associated with an increased risk of osteopenia or osteoporosis, unlike mercury. Subgroup analyses showed cadmium exposure increased the risk of osteopenia or osteoporosis in older (> 65 yrs.; OR = 1.43; 95%CI: 1.08 to 1.88, P = 0.01) compared with younger (18-65 yrs.; OR = 1.24; 95% CI: 1.02 to 1.52, P = 0.03) adults. Also, lead exposure increased the risk in men (OR = 1.55; 95% CI: 1.15 to 2.09, P = 0.007) unlike in women. By contrast to urinary levels, blood (OR = 1.26; 95% CI: 1.08 to 1.47, P = 0.003) and dietary (OR = 1.46; 95% CI: 1.28 to 1.67, P < 0.001) levels of cadmium were associated with an increased risk of osteopenia or osteoporosis. Exposure to cadmium and lead may be associated with an increased risk of osteopenia or osteoporosis, although high heterogeneity was detected.

Association between exposure to polychlorinated biphenyls and risk of hypertension: A systematic review and meta-analysis

Experimental and epidemiological studies have suggested an association between exposure to polychlorinated biphenyls (PCBs), ubiquitous environmental toxic compounds, and the risk of hypertension. We conducted a systematic review and meta-analysis of epidemiological studies of the association between PCB exposure and the risk of hypertension. Studies were identified by searching PubMed, Embase and Web of Science and by reviewing reference lists. Study-specific risk estimates comparing the highest versus lowest quantile of PCB distribution were combined using random-effects models. We identified 10 cross-sectional studies, 6 cohort studies, and 1 nested case-control study. A pooled excess risk of hypertension was found for total PCBs (OR 1.70, 95% CI 1.28-2.26), dioxin-like (DL)-PCBs (OR 1.46, 1.19-1.79), but not for non-dioxin like (NDL)-PCBs (OR 1.19, 0.81-1.73) comparing the highest with the lowest quartile of the distribution. According to a dose-response meta-analysis, a linear dose-effect relationship was found for total PCBs [OR 2.23 (95% CI: 1.59-3.14) for 1000 ng PCB/g lipid increase]. This positive association remained when stratifying the analyses by study design (cohort vs cross-sectional studies) and population (general population vs high exposed workers/residents). Among single PCB congeners, DL-PCB 105 and 118, and non-DL-PCB138 and 153 were related to hypertension. In conclusion, this meta-analysis suggests that exposure to PCBs, particularly to DL-PCBs, may be a risk factor for hypertension, independently of other risk factors.

Polychlorinated biphenyl serum levels, thyroid hormones and endocrine and metabolic diseases in people living in a highly polluted area in North Italy: A population-based study

Polychlorinated biphenyls (PCBs) are persistent organic pollutants produced until the 1980s, which they are still present worldwide. They have been associated with metabolic and endocrine diseases and hypertension in humans, but definite evidence is lacking. A chemical factory producing PCBs caused a heavy pollution in an urban area in Northern Italy. We aimed to evaluate present PCBs serum levels according to demographic and lifestyle variables and their associations with endocrine and metabolic diseases and hypertension in the resident general population. A random sample of 816 adults aged 20–79 years (mean ± SD: 49.1 ± 16.5 years) was enrolled in a cross-sectional population-based study. The participants provided a fasting blood sample for laboratory analysis and were face-to-face interviewed about the presence of chronic diseases. The serum level of total PCBs was computed as the sum of 33 PCB congeners. The median serum level of lipid-adjusted total PCBs was 435.2 and 95^th centile was 2154.9 ng/g lipid. Medium and high chlorinated PCBs with immunotoxic and endocrine disrupting activity contributed most to total PCB serum levels, particularly PCBs 138, 153, 170, 180 and 194. The serum levels of total PCBs and of PCB functional groups were positively associated with age and negatively with female gender, education, smoking habit and BMI, and not associated with serum levels of thyroid hormones and TSH and glycaemia and with presence of endocrine diseases, diabetes and hypertension by multivariable analysis. Subgroup analyses according to gender, age and BMI provided similar results. In conclusion, this study shows a long-term persistence of past exposure to PCBs and does not support the hypothesis of an association between PCB exposure and prevalence of endocrine and metabolic diseases and hypertension.

Factors associated with plasma concentrations of polychlorinated biphenyls (PCBs) and dichlorodiphenyldichloroethylene (p,p'-DDE) in the Canadian population

This study describes blood plasma concentrations of PCBs and p,p'-DDE in the Canadian population aged 20-79 years. PCBs and p,p'-DDE were measured in 1668 participants in the Canadian Health Measures Survey, Cycle 1 (2007-2009). We investigated how concentrations vary by sociodemographic, anthropometric, and lifestyle variables, identified factors associated with exposures, and evaluated concentrations against health-based guidance values. Congeners of PCB most commonly detected were PCB-138, PCB-153, and PCB-180. p,p'-DDE was detectable in > 99% of the samples. Factors associated with ∑PCBs were age, region of birth, frequency of fish consumption, and liver intake (R² = 58.1%). For p,p'-DDE, significant factors were sex, age, region of birth, household education, and ethnic origin (R² = 47.0%). PCB concentrations in Canadians were similar to those in the United States, and lower than those reported in Europe. A small percentage equalled or exceeded the Human Biomonitoring value of 3.5 µg/L for PCBs. Few exceedances of the p,p'-DDE biomonitoring equivalent were observed.

The effect of redox capacity of humic acids on hexachlorobenzene dechlorination during the anaerobic digestion process

Hexachlorobenzene (HCB) dechlorination affected by humic acids (HA) was evaluated in terms of HA redox capacity, HA concentrations, and microbial community, as well as the correlation between HA redox capacity values and HCB concentrations. With addition of HA in the initial stage, redox capacity values increased by 2.19 meq/L (80 mg/L of HA addition, HA₈₀), 2.51 meq/L (120 mg/L of HA addition, HA₁₂₀), and 3.64 meq/L (200 mg/L of HA addition, HA₂₀₀), respectively. The addition of HA could prominently enhance the HCB degradation rate. However, the concentration and the redox capacity of HA decreased during the anaerobic digestion process. Illumina MiSeq sequencing showed that microbial community affected by HA. Bacillus, Comamonas, and Pseudomonas were the predominant genera during the HCB dechlorination treatment. Moreover, Bacillus and Pseudomonas can improve HA electron transfer capability and promote the dechlorination of HCB.

Rationale for Environmental Hygiene towards global protection of fetuses and young children from adverse lifestyle factors

BACKGROUND

The regulatory management of chemicals and toxicants in the EU addresses hundreds of different chemicals and health hazards individually, one by one. An issue is that, so far, the possible interactions among chemicals or hazards are not considered as such. Another issue is the anticipated delay of several decades before effective protection of public health by regulatory decisions due to a time consuming process. Prenatal and early postnatal life is highly vulnerable to environmental health hazards with lifelong consequences, and a priority period for reduction of exposure. There are some initiatives regarding recommendations for pregnant women aiming at protection against one or another category of health hazard, however not validated by intervention studies.

HYPOTHESIS

Here, we aim at strengthening the management of exposure to individual health hazards during pregnancy and lactation, with protective measures in a global strategy of Environmental Hygiene. We hypothesize that such a strategy could reduce both the individual effects of harmful agents in complex mixtures and the possible interactions among them. A panel of experts should develop and endorse implementable measures towards a protective behavior. Their application is meant to be preferably as a package of measures in order to maximize protection and minimize interactions in causing adverse effects. Testing our hypothesis requires biomonitoring studies and longitudinal evaluation of health endpoints in the offspring. Favorable effects would legitimate further action towards equal opportunity access to improved environmental health.

CONCLUSION

Environmental Hygiene is proposed as a global strategy aiming at effective protection of pregnant women, unborn children and infants against lifelong consequences of exposure to combinations of adverse lifestyle factors.

Disparities in Environmental Exposures to Endocrine-Disrupting Chemicals and Diabetes Risk in Vulnerable Populations

Burgeoning epidemiological, animal, and cellular data link environmental endocrine-disrupting chemicals (EDCs) to metabolic dysfunction. Disproportionate exposure to diabetes-associated EDCs may be an underappreciated contributor to disparities in metabolic disease risk. The burden of diabetes is not uniformly borne by American society; rather, this disease disproportionately affects certain populations, including African Americans, Latinos, and low-income individuals. The purpose of this study was to review the evidence linking unequal exposures to EDCs with racial, ethnic, and socioeconomic diabetes disparities in the U.S.; discuss social forces promoting these disparities; and explore potential interventions. Articles examining the links between chemical exposures and metabolic disease were extracted from the U.S. National Library of Medicine for the period of 1966 to 3 December 2016. EDCs associated with diabetes in the literature were then searched for evidence of racial, ethnic, and socioeconomic exposure disparities. Among Latinos, African Americans, and low-income individuals, numerous studies have reported significantly higher exposures to diabetogenic EDCs, including polychlorinated biphenyls, organochlorine pesticides, multiple chemical constituents of air pollution, bisphenol A, and phthalates. This review reveals that unequal exposure to EDCs may be a novel contributor to diabetes disparities. Efforts to reduce the individual and societal burden of diabetes should include educating clinicians on environmental exposures that may increase disease risk, strategies to reduce those exposures, and social policies to address environmental inequality as a novel source of diabetes disparities.

Potential contribution of insecticide exposure and development of obesity and type 2 diabetes

The introduction of insecticides has greatly improved agricultural productivity and human nutrition; however, the wide use of insecticides has also sparked growing concern over their health impacts. Increased rate of cancers, neurodegenerative disorders, reproductive dysfunction, birth defects, respiratory diseases, cardiovascular diseases and aging have been linked with insecticide exposure. Meanwhile, a growing body of evidence is suggesting that exposure to insecticides can also potentiate the risk of obesity and type 2 diabetes. This review summarizes the relationship between insecticide exposure and development of obesity and type 2 diabetes using epidemiological and rodent animal studies, including potential mechanisms. The evidence as a whole suggests that exposure to insecticides is linked to increased risk of obesity and type 2 diabetes.

Health risk assessment of cadmium pollution emergency for urban populations in Foshan City, China

With rapid socioeconomic development, water pollution emergency has become increasingly common and could potentially harm the environment and human health, especially heavy metal pollution. In this paper, we investigate the Cd pollution emergency that occurred in the Pearl River network, China, in 2005, and we build a migration and transformation model for heavy metals to simulate the spatiotemporal distribution of Cd concentrations under various scenarios of Cd pollution emergency in Foshan City. Moreover, human health hazard and carcinogenic risk for local residents of Foshan City were evaluated. The primary conclusions were as follows: (1) the number of carcinogen-affected people per year under scenario 1 reached 254.41 when the frequency was 0.1 year/time; specifically, the number of people with cancer per year in the area of the Datang, Lubao, and Nanbian waterworks was 189.36 accounting for 74% of the total number per year; (2) at the frequency of 5 years/time, the Lubao waterwork is the only one in extremely high- or high-risk grade, while besides it, the risk grade in the Datang, Nanbian, Xinan, Shitang, and Jianlibao waterworks is in the extremely high or high grade when the frequency is 0.1 year/time; (3) when Cd pollution accidents with the same level occurs again, Cd concentration decreases to a low level in the water only if the migration distance of Cd is at least 40-50 km. Based on the health risk assessment of Cd pollution, this study gives the recommendation that the distance should keep above 50 km in tidal river network of the Pearl River Delta between those factories existing the possibility of heavy metal pollution and the drinking water source. Only then can the public protect themselves from hazardous effects of higher levels of heavy metal.

Serum concentrations of polychlorinated biphenyls (PCBs) in a Lebanese population: ENASB study

Polychlorinated biphenyls (PCBs) are persistent organic pollutants that are still routinely detected 30 years after their restriction in many countries. PCBs have been associated with several non-communicable diseases. They are best measured via human biomonitoring (HBM). The concentrations of six indicator PCBs (PCBs 28, 52, 101, 138, 153, and 180) were measured in the serum samples of 316 Lebanese students and employees from Saint Joseph University of Beirut, Lebanon, using gas chromatography coupled to an iron trap mass spectrometer detector. PCBs were detected in 56.3 to 59.2% of the serum samples. The sum of PCB (∑PCBs) levels ranged from <LOD to 338.84 ng/g lipids, with a geometric mean level of 10.34 ± 0.98 ng/g lipids. The major contributor to the ∑PCBs was PCB 180. In the present study, the levels were, in general, lower than the values observed in several Western and European countries. No association was found between age and concentration of any of the PCBs. In terms of risk for health, the highest levels were lower than critical limits such as HBM I and II values. We observed an inverted U-shaped association between levels of serum PCBs and the risk of overweight/obesity (OR = 2.140; CI = 1.095-4.185; p = 0.026). Regarding potential food contributors, we found no relation between PCB levels and fish consumption and a moderate relation with dairy product consumption (moderate consumers of dairy products had higher PCB levels compared to lower consumers) (16.92 ± 0.1/6.92 ± 0.12; p = 0.025). The present study is the first to provide information regarding PCB levels in a Lebanese population. Larger studies are required in order to estimate the PCB exposure parameters of the Lebanese population.

Polychlorinated biphenyl exposure alters the expression profile of microRNAs associated with vascular diseases

Exposure to persistent organic pollutants, including polychlorinated biphenyls (PCBs) is correlated with multiple vascular complications including endothelial cell dysfunction and atherosclerosis. PCB-induced activation of the vasculature subsequently leads to oxidative stress and induction of pro-inflammatory cytokines and adhesion proteins. Gene expression of these cytokines/proteins is known to be regulated by small, endogenous oligonucleotides known as microRNAs that interact with messenger RNA. MicroRNAs are an acknowledged component of the epigenome, but the role of environmentally-driven epigenetic changes such as toxicant-induced changes in microRNA profiles is currently understudied. The objective of this study was to determine the effects of PCB exposure on microRNA expression profile in primary human endothelial cells using the commercial PCB mixture Aroclor 1260. Samples were analyzed using Affymetrix GeneChip® miRNA 4.0 arrays for high throughput detection and selected microRNA gene expression was validated (RT-PCR). Microarray analysis identified 557 out of 6658 microRNAs that were changed with PCB exposure (p<0.05). In-silico analysis using MetaCore database identified 21 of these microRNAs to be associated with vascular diseases. Further validation showed that Aroclor 1260 increased miR-21, miR-31, miR-126, miR-221 and miR-222 expression levels. Upregulated miR-21 has been reported in cardiac injury while miR-126 and miR-31 modulate inflammation. Our results demonstrated evidence of altered microRNA expression with PCB exposure, thus providing novel insights into mechanisms of PCB toxicity.

Combined Effects of Prenatal Exposures to Environmental Chemicals on Birth Weight

Prenatal chemical exposure has been frequently associated with reduced fetal growth by single pollutant regression models although inconsistent results have been obtained. Our study estimated the effects of exposure to single pollutants and mixtures on birth weight in 248 mother-child pairs. Arsenic, copper, lead, manganese and thallium were measured in cord blood, cadmium in maternal blood, methylmercury in maternal hair, and five organochlorines, two perfluorinated compounds and diethylhexyl phthalate metabolites in cord plasma. Daily exposure to particulate matter was modeled and averaged over the duration of gestation. In single pollutant models, arsenic was significantly associated with reduced birth weight. The effect estimate increased when including cadmium, and mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP) co-exposure. Combining exposures by principal component analysis generated an exposure factor loaded by cadmium and arsenic that was associated with reduced birth weight. MECPP induced gender specific effects. In girls, the effect estimate was doubled with co-exposure of thallium, PFOS, lead, cadmium, manganese, and mercury, while in boys, the mixture of MECPP with cadmium showed the strongest association with birth weight. In conclusion, birth weight was consistently inversely associated with exposure to pollutant mixtures. Chemicals not showing significant associations at single pollutant level contributed to stronger effects when analyzed as mixtures.

Exposure and risk assessment of the Czech population to chlorinated pesticides and polychlorinated biphenyls using archived serum samples from the period 1970 to 1990

The serum samples from the years 1970-1990 archived at the temperature of -20°C in the biobank primarily intended for serological survey performed in the CR since 1960 were pooled and analyzed for DDT, its metabolites, HCB, HCHs, and indicator PCB congeners using up-to-date GC/MS/MS methods to retrospectively assess health risks according to current health guidelines. Samples were pooled based on the decade of sampling, age, gender, and three geographical areas; in adults, one pooled samples consisted of ten and in children of twenty individual samples. Altogether 233 pooled samples were analyzed. For all organochlorine pesticides (OCPs), significant downward trends were observed in the period 1970-1990 (p<0.001). The levels of HCB exceeded the Biomonitoring Equivalent (BE) value. The hazard quotient (HQ) in Prague and Ostrava during the 1970s and 1980s was about 40 and in the 1990s it had dropped to about five. In Uherské Hradiště, the HQ in 1975 was one order of magnitude higher (about 170), and had decreased to approximately 12 by 1987. For both HCB and the DDT sum, the BE-related carcinogenic risk of actual concentrations in the past exceeded significantly the individually accepted cancer risk level of 10(-4). The levels of the main PCB congeners in the 1970s through 1990s revealed an upward time trend in all analyzed strata. The highest concentrations were found in the serum of residents from the hot-spot area Uherské Hradiště. Critical PCB sum concentration levels (700ng/g lipid for vulnerable population groups and 1800ng/g lipid for other population groups) were substantially exceeded with an increasing time trend. PCB sum had exceeded HBM II values of 7μg/L of serum since 1980 in all age strata. In conclusion, the body burden of the Czech general population relative to persistent organic pollutants (POPs) in the period 1970 through 1990 significantly exceeded currently existing health based limit values. The past exposure might adversely affect the health status of the Czech population.

Self-rated health and chronic conditions are associated with blood concentrations of persistent organic pollutants in the general population of Catalonia, Spain

BACKGROUND

Self-rated health (SRH) is a powerful predictor of mortality, morbidity, and need for health services. SRH generally increases with educational level, and decreases with age, number of chronic conditions, and body mass index (BMI). Because human concentrations of most persistent organic pollutants (POPs) also vary by age, education, and BMI, and because of the physiological and clinical effects of POPs, we hypothesized that body concentrations of POPs are inversely associated with SRH.

OBJECTIVES

To analyze the relation between serum concentrations of POPs and SRH in the general population of Catalonia, Spain, taking into account sociodemographic factors and BMI, as well as chronic health conditions and mental disorders, measured by the General Health Questionnaire-12 (GHQ-12).

METHODS

POP serum concentrations were measured by gas chromatography with electron-capture detection in 919 participants of the Catalan Health Interview Survey.

RESULTS

Individuals with higher concentrations of POPs had significantly poorer SRH; e.g., the median concentration of HCB in subjects with poor SRH was twice as high as in subjects with excellent SRH (366 ng/g vs. 169 ng/g, respectively; p-value<0.001). In crude models and in models adjusted for sex and BMI, the POPs-SRH association was often dose-dependent, and the likelihood of poor or regular SRH was 2 to 4-times higher in subjects with POP concentrations in the top quartile. In models adjusted for age or for chronic conditions virtually all ORs were near unity. No associations were found between POP levels and GHQ-12.

CONCLUSIONS

Individuals with higher concentrations of POPs had significantly poorer SRH, an association likely due to age and chronic conditions, but not to sex, education, social class, BMI, or mental disorders.