Levels of Octachlorostyrene in Mothers' Milk and Potential Exposure Among Infants in Sendai City, Japan 2012

Chlorinated persistent organic pollutants in human breast milk in the Miyagi Prefecture disaster-affected area 1 year after the Great East Japan Earthquake of 2011

BACKGROUND

In the Great East Japan Earthquake of 11 March 2011, an earthquake and accompanying tsunami struck the Tohoku region of northeastern Japan. Buildings collapsed and the tsunami spread waste, including hazardous materials. This study aimed to determine the concentrations of persistent organic pollutants (POPs) in the breast milk of mothers living in the disaster-affected area of Sendai 1 year after the earthquake. Temporal trends in the POPs concentrations were evaluated by comparison with previous studies.

METHODS

One hundred breast milk samples were obtained from lactating mothers at a hospital in Sendai in 2012. The results were compared with those from other years to examine whether there were changes in the POPs concentrations after the earthquake. We measured polychlorinated biphenyls (PCBs) and organochlorine pesticides, such as chlordanes, using gas chromatography-mass spectrometer (GC-MS) with negative chemical ionization, and dichlorodiphenyl trichloroethane (DDT) and its metabolites using GC-MS with electron impact ionization.

RESULTS

The mean total PCBs (11 congeners), total chlordane, and total DDT concentrations were 76.2 ng/g lipid, 39.8 ng/g lipid, and 73.5 ng/g lipid, respectively. For the samples collected in 2012, the concentrations of POPs in breast milk showed minimal changes compared with results from previous years for samples collected at the same hospital in Sendai.

CONCLUSIONS

Our study demonstrates that 1 year after the earthquake and tsunami, the concentrations of chlorinated POPs in breast milk had not changed substantially.

Toxicity Assessment of Octachlorostyrene in Human Liver Carcinoma (HepG2) Cells

Octachlorostyrene (OCS) is a ubiquitous persistent organic pollutant; however, information regarding the toxicological effects of OCS remains limited. In this study, we studied the toxicity mechanisms of OCS using human liver carcinoma (HepG2) cells. The results showed that OCS reduced cell viability in a time- and dose-dependent manner. Compared with that in the control, the level of reactive oxygen species (ROS) was significantly increased in all treated HepG2 cells. We also found that (1) OCS induced damage in the HepG2 cells via the apoptotic signaling pathway, (2) OCS increased intracellular free Ca²⁺ concentration (>180%), and (3) following exposure to 80 μM OCS, there was an increase in mitochondrial transmembrane potential (MMP, ~174%), as well as a decrease in ATP levels (<78%). In conclusion, OCS is cytotoxic and can induce apoptosis, in which ROS and mitochondrial dysfunction play important roles; however, the observed increase in MMP appears to indicate that HepG2 is resistant to the toxicity induced by OCS.

Surface-Encapsulated Bismuth Molybdate-Layered Silicate Hybrids as Sorbents for Photocatalytic Filtration Membranes

Groundwater is being depleted globally at an average rate of more than one meter per year, during a period when more than a quarter of the human population has no access to potable water. Aside from overexploitation, freshwater security is also threatened by climate change and chemical pollution. The contamination of surface and groundwater by industrial substances is also undermining the vitality of ecosystems. It was previously shown that {100}-faceted Bi2MoO6-Laponite hybrids effectively bind and photodegrade molecular species, aiding in the decontamination of water. In this study, the encapsulation of Bi2MoO6-Laponite particles with the polymers butyl acrylate and styrene further enhanced adsorption of methylene blue by 31.4%, with a specific adsorption capacity of 192 μmol/g. The polymer-particle composites were deposited to form membranes and their efficacies in water filtration and photodegradation were examined. Among the different surface modifications examined, the highest dye sorption was obtained by butyl acrylate and styrene (3:2) with a 5 mol % cross-linker. This study provides a method for enhancing the molecular adsorption of composite particles used in membranes capable of multiple cycles of adsorption and photodegradation, advancing the application of such systems to water filtration.

Chemical pollution: A growing peril and potential catastrophic risk to humanity

Anthropogenic chemical pollution has the potential to pose one of the largest environmental threats to humanity, but global understanding of the issue remains fragmented. This article presents a comprehensive perspective of the threat of chemical pollution to humanity, emphasising male fertility, cognitive health and food security. There are serious gaps in our understanding of the scale of the threat and the risks posed by the dispersal, mixture and recombination of chemicals in the wider environment. Although some pollution control measures exist they are often not being adopted at the rate needed to avoid chronic and acute effects on human health now and in coming decades. There is an urgent need for enhanced global awareness and scientific scrutiny of the overall scale of risk posed by chemical usage, dispersal and disposal.

Absence of Detectable Radionuclides in Breast Milk in Sendai, Japan in 2012 Even by High-Sensitivity Determination: Estimated Dose among Infants after the Fukushima Nuclear Disaster

The aim of this study was to estimate radionuclide levels in breast milk and the transferred dose to their infants in Sendai (100 km from Fukushima), Japan after the 2011 Fukushima nuclear disaster. Radionuclide concentrations were analyzed in 101 specimens of breast milk collected in 2012. Median values for minimum detectable activities were 0.39, 0.34, 1.1, 1.89, and 17.1 Bq/kg for ¹³⁷Cs, ¹³⁴Cs, ¹³¹I, ^110mAg, and ⁴⁰K, respectively. Only radionuclides from ⁴⁰K were detected. To estimate potential exposure and radiocesium dose, we assumed that the samples contained each minimum detectable activity level. The mean minimum detectable activity concentrations (standard deviation) of ¹³⁷Cs and ¹³⁴Cs were 0.42 (0.15) and 0.37 (0.14) Bq/kg, respectively. Means of estimated dietary intakes of ¹³⁷Cs and ¹³⁴Cs among infants were 0.35 (0.12) and 0.31 (0.11) Bq/day, respectively. The committed effective doses of radiocesium in infants aged 3 and 12 months via breastmilk were estimated at 5.6 (2.1) and 3.3 (1.2) μSv/year, respectively. Dietary intakes of ¹³⁷Cs and ¹³⁴Cs in breastfeeding mothers were back-calculated at 1.9 (0.71) and 1.7 (0.65) Bq/day, respectively. The study verified no discernible exposure to radionuclides among infants. The most conservative estimates were below the Japanese internal exposure limit of 1 mSv/year.

Systematic Review Protocol for the Current State of Chemical Exposure in Infants via Breast Milk, Artificial Milk and Dairy Products

Many studies have shown that human breast milk is contaminated with various chemicals. In the proposed systematic review, the aim is to identify and summarize the available literature regarding chemical exposure via breastfeeding or the feeding of artificial formula. MEDLINE (PubMed) will be the primary source in this literature search. Primary studies that analyzed one or more chemicals of interest in breast milk or artificial milk and that reported information on concentrations will be eligible for this review. Conference abstracts will not be included in the review unless access to the data is easy. First, the titles and abstracts of identified articles will be screened by two or more researchers. Then, a full-text review will be conducted to extract data from the included articles and code them for classification. The results of the search and classification will be summarized narratively and bibliometrically. The aim of the review is to analyze trends in publications according to year and region from the viewpoint of target chemicals, location, range of concentrations, and health outcomes.

Estimation of dietary intake and sources of organohalogenated contaminants among infants: 24-h duplicate diet survey in Fukuoka, Japan

The widespread occurrence of persistent organic pollutants (POPs) in the environment is a matter of concern. In this study, selected organohalogenated contaminants, including dichlorodiphenyltrichloroethane and its metabolites (DDTs) polychlorinated biphenyls (PCBs), chlordanes (CHLs), hexachlorobenzene (HCB), polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDs), tetrabromobisphenol A (TBBPA), 2,4,6-tribromophenol (TBP), were measured in complete meal sets (24-h duplicate-diet) of Japanese infants to investigate the levels, profiles, and possible sources of contamination. In total, 46 whole-day meals of infants (7-24-months old) were collected during 2017 from Fukuoka, Japan. To the best of our knowledge, this is the first report based on the duplicate-diet method for infants. The median intakes among the POP groups were highest for ΣDDTs (18 ng/day, maximum 251 ng/day), followed by ΣPCBs (17 ng/day, maximum 198 ng/day), ΣCHLs (14 ng/day, maximum 105 ng/day), HCB (11 ng/day, maximum 64 ng/day), TBP (3.5 ng/day, maximum 109 ng/day), ΣHBCDs (1.9 ng/day, maximum 70 ng/day), TBBPA (0.72 ng/day, maximum 34 ng/day), and ΣPBDEs (0.11 ng/day, maximum 4.5 ng/day). Among the PCBs, PCB-138 and PCB-153 were the most abundant congeners (27% and 23%, respectively). p,p'-DDE, the major DDT metabolite, accounted for 96% of total DDTs. Among PBDEs, BDE47 was the only detected congener (present in 4% of the samples). The dietary intake of the targeted compounds was lower than the intake via breast milk, suggesting that the exposure from baby food was limited. In the principal component analysis, chlorinated and brominated compounds were separated on principal component 1, while TBP and α-HBCD were separated on principal component 2, likely suggesting a differing emission time trend or source. PCB-153, PCB-138, trans-chlordane, cis-chlordane, and trans-nonachlor were correlated with seafood consumption (Spearman's ρ = 0.45 to 0.57, p < 0.05), while TBP was correlated with seaweed consumption (Spearman's ρ = 0.46, p < 0.05). Also, four species of commercial edible seaweed in Japan were analyzed to confirm the findings of the duplicate-diet study. The relatively high concentration of TBP (5.5 ± 6.6 ng/g wet weight) was observed in the seaweed samples, indicating that seaweed is a potential exposure source of TBP.