Levels and regional trends of persistent organochlorines and polybrominated diphenyl ethers in Asian breast milk demonstrate POPs signatures unique to individual countries

Human breast milk samples collected in 2007–2008 from four countries, Vietnam (Hanoi), China (Beijing), Korea (Seoul) and Japan (Sendai, Kyoto and Takayama), were analyzed for persistent organic pollutants (POPs) such as dichlorodiphenyltrichloroethane and its metabolites (DDTs), chlordane-related compounds (CHLs), hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). Comparing with previous surveys, the present study indicates that the DDTs in breast milk from China and Vietnam had gradually decreased during the last decade, but were still 5–10 times higher than those in other nations. The ratios of p,p′-DDE/p,p′-DDT and o,p′-DDT/p,p′-DDT were higher in Beijing than in the other countries, suggesting that there is less fresh intake of commercial DDT products and a possible exposure to dicofol in China. CHL and PCB levels were relatively higher in mothers from Japan, whereas β-HCH and HCB were more common in Chinese women. In Japan, it is suspected that mothers in the urban/coastal area (Sendai) were more continuously exposed to organochlorine pesticides (OCPs) than mothers in the rural/inland area (Takayama). In addition, OCP levels in primiparae were significantly higher than those in multiparae from Japan and Korea. These indicate that both parity and regional factors are major determinants of the levels of OCPs and PCBs in human milk. On the other hand, higher concentrations of PBDEs were observed in mothers' milk from Korea. The congener was dominated by BDE-47 (43–54%), followed by BDE-153 (23–33%) in all regions except for Beijing where BDE-28 (23%) was relatively abundant. In Japanese breast milk, regional and parity-dependent distributions were not observed for PBDEs. Among PBDE congeners, age-dependency was observed for BDE-153, which was negatively correlated (p < 0.05) to the age of mothers in Kyoto (17 participants were housewives), while it increased with age in Sendai (10 participants were clerks). No such correlation was seen for BDE-47, indicating that BDE-47 was ingested and assimilated via different kinetics or routes from BDE-153 in Japan.     

Lysis of cyanobacteria with volatile organic compounds

One of bacteria collected from Lake Sagami, Japan, Brevibacillus sp., was found to have a lytic activity of cyanobacteria, but did not produce active compounds. Instead, the co-culturing of Microcystis with the Brevibacillus sp. enhanced the production of two volatile compounds, beta-cyclocitral and 3-methyl-1-butanol, and the former had a characteristic lytic activity. It was confirmed that these volatile compounds were derived from the cyanobacteria themselves. beta-Ionone, geosmin and 2-methylisoborneol derived from cyanobacteria and similar volatile compounds, terpenoids, produced by plants also had a lytic activity. The minimum inhibitory concentration values of the cyanobacterial metabolites were estimated to be higher than those of compounds from plants except for a few compounds. Among them, beta-cyclocitral only produced a characteristic color change of culture broth from green to blue. This color change is similar to the phenomenon observed when a sudden decline in growth of cyanobacteria begins in a natural environment.     

Polychlorinated biphenyls and Organochlorine insecticides residues in fish and shellfish from lake Biwa

Results of surveys on Polychlorinated biphenyls (PCB) and organochlorine insecticides (HCH and DDT) in fish and shellfish from Lake Biwa were summarized from 1987 to 1996. In 1975, fish and shellfish in Lake Biwa were highly contaminated with PCB, HCH and DDT but recently in 1992–1996 the concentrations of these chemicals were very low and nearly constant. In the composition of HCH isomers, β‐HCH was dominant in all kinds of fish and shellfish. In the composition of DDT and DDT metabolites, pp'‐DDE was similarly dominant in all kinds of fish and shellfish. Further, the data in Lake Biwa were compared with those in Lake Michigan and Lake Baikal.     

Leaching of heavy metals by citric acid from fly ash generated in municipal waste incineration plants

The leaching behavior of heavy metals from municipal waste incineration (MWI) fly ash was investigated in this study. The leaching process includes two steps, i.e., fly ash was firstly washed with water, and then subjected to citric acid leaching. The main parameters of the washing process such as liquid/solid ratio, washing time, and number of washing were tested. The optimum conditions for water washing were found as follows: washing time 5–10 min, liquid/solid ratio 10:1 (ml:g), and number of washing was twice; under these conditions, 86% Na, 70% K, 12% Ca, 1.2% Al, and 0.5% Pb were removed from the fly ash in the prewashing. From the results of screening tests of leaching lixiviants, citric acid was found to be the most effective leaching agent, taking account of its environmentally benign characteristics. Optimum metal extraction can be achieved with citric acid under the following conditions: pH 3.0, liquid/solid ratio 40 (ml:g), citric acid concentration 0.10 mol/dm³, contact time 20 min at room temperature.     

Analysis of perfluoroalkyl carboxylates in vacuum cleaner dust samples in Japan

Perfluorooctanoic acid (PFOA) has long been an environmental contaminant of concern owing to its potential health risk. However, exposure to perfluorinated carboxylic acids (PFCAs) other than PFOA is not well understood. In this study, we investigated the concentrations of PFCAs in vacuum cleaner dust in Japan to measure the PFCAs contamination in an indoor environment. Most of the 77 samples contained PFCAs with 6-13 carbon atoms. The median concentration of perfluorononanoic acid (PFNA, 23.2 ng g⁻¹) was highest among PFCAs, followed by PFOA (20.8 ng g⁻¹) and perfluoroundecanoic acid (PFUnDA, 12.9 ng g⁻¹). The 90th percentile concentrations of PFNA, PFUnDA and perfluorotridecanoic acid (PFTrDA) were 948, 283 and 110 ng g⁻¹, respectively, and these were detected at greater concentrations than neighboring, even-numbered PFCAs. The proportion of long-chain PFCAs in vacuum cleaner dust from Japan was relatively higher than those reported for other countries. Factor analysis showed three independent factors. Odd-numbered long chain PFCAs (PFNA, PFUnDA and PFTrDA), which can correspond to factor 1, were major components of PFCAs in vacuum cleaner dust. Short chain PFCAs (factor 2) and even numbered long chain PFCAs (factor 3) were also statistically separated. These findings suggest that there are several sources of PFCAs with different origins in indoor environment. Further investigations into the origins of PFCAs are needed to evaluate indoor contamination with PFCAs.     

A global transport model of lead in the atmosphere

A global atmospheric transport model is used to calculate lead concentrations in the atmosphere. The model performance is evaluated through comparisons with observations in Europe. The model results of lead concentrations in surface air were compared with measurements in East Asia. The detailed comparisons showed generally good agreement for recent decades, although systematic underestimation was found in China. Anthropogenic lead emissions in China are estimated from economic statistics to be 56 000 t yr^?1, which is not small considering the economic scale of China. The underestimations suggest a hidden source of lead emissions. The emissions in Japan and Korea are derived from optimization by the model. The magnitude is about 2000 t yr^?1, which is much greater than that reported by the Pollutant Release and Transfer Register in Japan and Toxics Release Inventory in Korea.     

Application of crosswell seismic tomography using difference analysis with data normalization to monitor CO2 flooding in an aquifer

A pilot-scale experiment for carbon dioxide (CO₂) sequestration was undertaken at the Nagaoka test field in Japan. Time-lapse crosswell seismic tomography was conducted to detect and monitor the movement of CO₂ injected into an aquifer. We applied difference analysis with data normalization (DADN) to the time-lapse data to eliminate false images that were apparent in a conventionally processed difference section. Conventional difference analysis calculates travel-time delays after inversion, whereas the DADN method calculates them from raw travel-time records before inversion. Thus, fewer errors are generated with the DADN method compared to a conventional inversion analysis. We applied the DADN method to time-lapse tomography data recorded before and after the injection of CO₂ and computed the velocity variation in a subsurface section, which clearly showed the distribution of CO₂ flooding within a high permeability zone in the aquifer and showed no CO₂ leakage into the caprock. Our results also show the maximum velocity decrease as a result of CO₂ injection was about 9%, which is close to the results obtained in laboratory experiments. Finally, numerical simulations were inverted to test the effectiveness of the conventional and DADN methods in dealing with noise. These tests showed that the DADN method effectively reduces unique coherent noise for particular receiver and source combinations. We concluded that the DADN method provides useful data for monitoring the flow of CO₂ sequestered in underground aquifers.     

Eco-balance analysis of land use combinations to minimize environmental impacts and maximize farm income in northern Japan

Relationships among global warming potential (GWP), farmland surplus nitrogen (FSN) and income for major land uses in the Ikushunbetsu watershed were compared using the eco-balance method. An empirical model was created for carbon dioxide, methane and nitrous oxide for both uplands and paddy rice using monitoring data from 22 fields. The greenhouse gas emissions were converted into GWP, whereas yield and FSN were obtained from interviews with farmers and a literature survey. Land use distribution was obtained by ground surveys in 2002, 2005 and 2007. The analysis showed that paddy rice and soybeans were characterized by a high GWP, low FSN and high income, whereas onions and vegetables had a high FSN but low GWP and moderate income. Wheat showed a negative GWP in some years, and abandoned areas always exhibited negative values. The total GWPs for the region were 14,184, 11,085 and 8,337 Mg CO₂ year⁻¹ for 2002, 2005 and 2007, respectively. The contribution of paddy rice to GWP was highest, ranging from 40 to 75%. To find optimal land use combinations that provide higher incomes and lower GWPs and FSNs than at present, all possible land use combinations were analyzed by changing the land use proportion from 0 to 100% at an interval of 10%. The number of land use combinations meeting the requirements in the three investigated years was 205. Abandoned area, which had the smallest environmental load, was included in every land use combination, indicating that land uses with low environmental impacts should be maintained at a certain proportion to mitigate the environmental load accompanying land uses with high production.     

Removal of mercury using processes involving sulfuric acid during zinc production in an imperial smelting process (ISP) plant

Journal of Material Cycles and Waste Management - Mercury emissions from non-ferrous metal industries are a major environmental concern. Because of the large differences in mercury emission factors...