Waste prevention for sustainable resource and waste management

Although the 2Rs (reduce and reuse) are considered high-priority approaches, there has not been enough quantitative research on effective 2R management. The purpose of this paper is to provide information obtained through the International Workshop in Kyoto, Japan, on 11–13 November 2015, which included invited experts and researchers in several countries who were in charge of 3R policies, and an additional review of 245 previous studies. It was found that, regarding policy development, the decoupling between environmental pressures and economy growth was recognized as an essential step towards a sustainable society. 3R and resource management policies, including waste prevention, will play a crucial role. Approaches using material/substance flow analyses have become sophisticated enough to describe the fate of resources and/or hazardous substances based on human activity and the environment, including the final sink. Life-cycle assessment has also been developed to evaluate waste prevention activities. Regarding target products for waste prevention, food loss is one of the waste fractions with the highest priority because its countermeasures have significant upstream and downstream effects. Persistent organic pollutants and hazardous compounds should also be taken into account in the situation where recycling activities are globally widespread for the promotion of a material-cycling society.     

Trivalent chromium solubility and its influence on quantification of hexavalent chromium in ambient particulate matter using EPA method 6800

Measurement of carcinogenic Cr(VI) in ambient PM is challenging due to potential errors associated with conversion between Cr(VI) (a carcinogen) and Cr(III) (an essential nutrient). Cr(III) conversion is a particular concern due to its >80% atomic abundance in total Cr. U.S. Environmental Protection Agency (EPA) method 6800 that uses water-soluble isotope spikes can be used to correct the interconversion. However, whether the enriched Cr(III) isotope spikes can adequately mimic the Cr(III) species originally in ambient PM is unknown. This study examined the water solubility of Cr(III) in ambient PM and discussed its influence on Cr(VI) measurement. Ambient PM₁₀ samples were collected on Teflon filters at four sites in New Jersey that may have different Cr emission sources. The samples were ultrasonically extracted with 5 mL DI-H₂O (pH 5.7) at room temperature for 40 min, and then analyzed by ion chromatography–inductively coupled plasma mass spectrometry (IC-ICPMS). Cr(III) was below detection limit (0.06 ng/m³) for all samples, suggesting water-soluble Cr(III) species, such as CrCl₃, Cr(NO₃)₃, and amorphous Cr(OH)₃, in the ambient PM were negligible. Therefore, the enriched ⁵⁰Cr(III) isotope spike (in the form of Cr(NO₃)₃) could not mimic the original ambient Cr(III). Only the conversion of ⁵³Cr(VI) (in the form of K₂CrO₄) was taken into account when correcting the interconversion. We then used NaHCO₃-pretreated MCE filters (prespiked with enriched isotope species) to measure Cr(VI) in the ambient PM₁₀. The samples were ultrasonically extracted at 60 C pH 9 solutions for 40 min followed by IC-ICPMS analysis. Due to the correction of Cr(VI) reduction, the Cr(VI) concentrations determined by EPA method 6800, 0.26 ± 0.16 (summer) and 0.16 ± 0.11(winter) ng/m³ (n = 64), were significantly greater than those by the external standard curve, 0.21 ± 0.17 (summer) and 0.10 ± 0.07 (winter) ng/m³ (n = 56) (p < 0.01, Student’s t-test). Our study revealed that appropriate application of EPA method 6800 is important because it only applies to soluble fraction of Cr species in ambient PM.

ImplicationsAccurate measurement of carcinogenic Cr(VI) in ambient PM is challenging due to conversion between Cr(VI) (a human carcinogen) and Cr(III) (a human essential nutrient). The conversion of Cr(III) is of particular concern due to its dominant presence in total Cr (>80%). This study examined the water solubility of Cr(III) in ambient PM that was collected at four locations in New Jersey. Then we discussed the influence of Cr(III) solubility on the application of EPA method 6800, which utilizes enriched isotope spikes to correct the interconversion. Our results suggested that appropriate application of EPA method 6800 is important because it only applies to soluble fraction of Cr species.     

Development of a Marine Sediment Pollution Index.

To facilitate translation of the state of marine sediment quality for public information, a pollution index was developed from the results of a routine monitoring program. Principal component analysis (PCA) of 24 variables at 64 monitoring stations from 1987 to 1997 was carried out to identify the most important parameters that were applied in the index formulation. Of the 24 variables, six (Cr, Cu, Ni, chemical oxygen demand, Zn, Mn) were selected on the basis of their high PCA loadings. The derived Marine Sediment Pollution Index, rating from 0 to 100, reflected the general trend in the monitoring areas. The index was also found to have a significant negative correlation (P < 0.05) with the benthic species diversity and toxicity of the sediment, indicating its usefulness in reflecting marine sediment quality. The application of PCA to identify important variables from a monitoring program would reduce sampling resources, as parameters that did not show significant spatial or temporal variations could be analyzed in a lesser frequency than those that were identified to be more important from the results of PCA.     

Temporal variation of volatile organic compounds and their major emission sources in Seoul, Korea

This study examines the characteristics of volatile organic compounds (VOCs) and their major emission sources at the Bulgwang site in Seoul, Korea. The annual levels of VOCs (96.2–121.1 ppb C) have shown a decreasing trend from 2004 to 2008. The most abundant component in Seoul was toluene, which accounted for over 23.5 % of the total VOCs on the parts per billion on a carbon basis, and the portions of alkanes with two to six carbons constituted the largest major lumped group, ranging from 40.1 to 48.4 % (45.3?±?3.7 %) of the total VOCs. Major components of the solvent (toluene, m/p-xylene, o-xylene, and ethylbenzene) showed high in daytime and summer and low in nighttime and winter due mainly to the variation of the ambient temperature. The species mostly emitted from gasoline vapor (i/n-butane, i/n-pentane, n-hexane, and 2-methylpentane) and vehicular exhaust (ethylene, acetylene, and benzene) showed bimodal peaks in the diurnal variation around the commuting hours because of the high traffic volume. For the 14 out of 15 highest concentration species, the weekend effect was only evident on Sundays because of the stepwise implementation of the 5-day work-week system. Principal components analysis (PCA) was applied in order to identify the sources of the 15 highest concentration VOCs and, as a result, three principal components such as gasoline vapor (48.9 %), vehicular exhaust (17.9 %), and evaporation of solvents (9.8 %) were obtained to explain a total of 76.6 % of the data variance. Most influential contributing sources at the sampling site were traffic-related ones although the use of solvent was the dominant emission source based on the official emission inventory.     

Sediment characteristics and colonization of soft-bottom benthos: a field manipulation experiment

A field manipulation experiment was carried out to test the effects of sediment characteristics (particle size and organic content) on colonization of soft-bottom benthos. Defaunated mud and sand in experimental trays were exposed at sub-tidal levels of two sites with sandy and muddy sea bottom, and retrieved monthly for examination of benthic composition. Seventy-eight out of the 107 species recorded, and 50% of the dominant species identified in the present study, were common in both the sand and mud trays. Classification analysis revealed higher faunal similarity of benthic composition in both sediment types within each of the two study sites. Results of three-way ANOVA (Sediment, Site and Time) showed that sediment effect was only significant for colonization of bivalves and gastropods, but not for polychaetes, amphipods, total species and individual numbers, or overall benthic diversity and evenness. This suggested that many of the benthic species can colonize both sediment types, and that factors other than sediment particle size and organic content may play a significant role in determining colonization of these species. The faunal composition of the same sediment type between sites was found to be different, indicating that the availability and abundance of benthic larvae/adults may be more important than sediment characteristics in determining benthic settlement. An increase in faunal similarity between mud and sand was observed over the study period, implying that the importance of sediment characteristics to benthic colonization decreased with exposure time. Received: 29 November 1996 / Accepted: 16 January 1997     

Allocation and source attribution of lead and cadmium in maize (Zea mays L.) impacted by smelting emissions

Plants grown in contaminated areas may accumulate trace metals to a toxic level via their roots and/or leaves. In the present study, we investigated the distribution and sources of Pb and Cd in maize plants (Zea mays L.) grown in a typical zinc smelting impacted area of southwestern China. Results showed that the smelting activities caused significantly elevated concentrations of Pb and Cd in the surrounding soils and maize plants. Pb isotope data revealed that the foliar uptake of atmospheric Pb was the dominant pathway for Pb to the leaf and grain tissues of maize, while Pb in the stalk and root tissues was mainly derived from root uptake. The ratio of Pb to Cd concentrations in the plants indicated that Cd had a different behavior from Pb, with most Cd in the maize plants coming from the soil via root uptake.     

Human exposure to PCBs, PBDEs and HBCDs in Ghana: Temporal variation, sources of exposure and estimation of daily intakes by infants

Human exposure to polychlorinated biphenyls (PCBs) and brominated flame retardants (BFRs) such as polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) was evaluated in Ghana using breast milk samples collected in 2004 and 2009. Mean levels and ranges of PBDEs (4.5; 0.86-18 ng/g lw) and PCBs (62; 15-160 ng/g lw) observed in the present study were unexpectedly high, in spite of the fact that Ghana is a non-industrialized country when compared with many of the Asian and European countries. Significant increases were found in the concentrations of PCBs and PBDEs over the years, while no significant increase was observed for HBCDs. Estimated hazard quotient (HQ) showed that all the mothers had HQ values exceeding the threshold of 1 for PCBs, indicating potential health risk for their children. PCBs in dirty oils and obsolete equipment should be of concern as potential sources in Ghana, and e-waste recycling with little or no experience in safe handling could be a threat to this sub-region noted for unregulated disposal of e-waste. The results may point towards an increase in trends in human milk in Ghana, especially in the larger cities but further analysis would be required to confirm this upward trend in levels. This is the first study to report BFRs in human breast milk from Africa, and undoubtedly from Ghana.     

Occurrence of perfluorooctanoate and perfluorooctanesulfonate in the Korean water system: implication to water intake exposure

Perfluorinated compounds (PFCs) measured in surface running waters indicated the existence of different emission sources in eight main city basins. The tap water reflected the contamination pattern and levels in their corresponding source water basins. The daily intakes through tap water consumption ranged from <0.01 to 0.73 ng kg⁻¹ d⁻¹ for perfluorooctanoate (PFOA) and <0.01 to 0.08 ng kg⁻¹ d⁻¹ for perfluorooctanesulfonate (PFOS). Tap water intake-derived exposure accounted for 8.6%-101% (for PFOA) and while <10% (for PFOS) of total daily exposure, which was estimated from Korean serum concentrations using a pharmacokinetic model. Our findings indicate that tap water intake could be an important contributor to PFOA exposure in Korean populations; accordingly, additional efforts are necessary to improve the removal efficiency of perfluorinated compounds (PFCs) in the water purification process. However, more fundamentally the aim would be to reduce the discharge of PFCs from potential sources within the basin.     

Associations of fat mass and lean mass with bone mineral density differ by levels of persistent organic pollutants: National Health and Nutrition Examination Survey 1999-2004

Persistent organic pollutants (POPs), xenobiotics that accumulate in fat tissue, may impair bone metabolism. We studied (1) the association of bone mineral density (BMD) with POPs and (2) whether associations of fat mass (FM) or lean mass (LM), two components of body composition, with BMD differed depending on levels of POPs. Participants aged ?20 in the National Health and Nutrition Examination Survey 1999-2004 were included (n = 2769). Eight POPs with detection rate ?80% and three skeletal subregions (left arm, pelvis, and right leg) were selected. All analyses were stratified by gender and age (cutpoint 50 years or more). POPs at background concentrations were mostly unassociated with BMD. However, the associations of FM and LM with BMD depended on POPs concentrations, in particular with BMD of the left arm (usually not weight-bearing) in postmenopausal women. When POPs concentrations were low, FM showed inverse associations with BMD while LM showed positive associations. However, when POPs levels were high, FM showed positive associations with BMD while the positive associations between LM and BMD weakened. POPs may biologically modify the associations of FM and LM with BMD, especially among postmenopausal women, possibly explaining inconsistent associations between FM and BMD in previous epidemiological studies.     

Geographical distribution and accumulation features of PBDEs in human breast milk from Indonesia

The present study reports concentrations of polybrominated diphenyl ethers (PBDEs) and organochlorines (OCs) in human breast milk from Indonesia covering urban, suburban and rural areas. PBDEs were detected in all the samples of the present study with total concentrations ranging from 0.49 to 13 ng/g lipid wt. Geographical distribution showed that concentrations of PBDEs were relatively uniform (p>0.05) and the levels were in the same order as those in Japan and some European countries, but were one or two order lower than North America. When compared to OCs, the level of total PBDEs was lower. The congener pattern was in accordance with other studies on human matrices, in which BDE-47 was the most abundant congener. Variations of PBDE congeners in human breast milk were further discussed to elucidate the potential exposure source(s) and pathways.