Using synchrotron- and electron microscope-based X-ray microanalyses, the distribution and speciation of Zn and Pb were examined in situ in two earthworm species (Dendrodrilus rubidus and Lumbricus rubellus) living in heavily-polluted soils. Main findings: (i) Zn spectra in ingested soil and in tissues more closely resembled Zn3(PO4)2 than ZnS; (ii) Zn speciation in tissues gave a best fit for Zn to the inner shell of 4 oxygens at 1.94 Å (or nitrogens at 1.96 Å); (iii) the best fit for Pb in tissue was with a shell of oxygens at 2.18 Å and a shell of sulphurs at 2.67 Å; (iv) a component of the Zn and much of the Pb detectable in gut contents was co-distributed with S; (v) Zn and Pb display ‘soft’ acid affinities in soil, but ‘hard’ acid affinities in tissue. This is the first metal characterisation study conducted on an invertebrate quench-frozen in the field.

The dissolution of ZnO nanoparticles (nano-ZnO) plays an important role in the toxicity of nano-ZnO to the aquatic organisms. The effects of water chemistry such as pH, ionic components, and dissolved organic matter (DOM) on the dissolution of nano-ZnO and its toxicity to Escherichia coli (E. coli) were investigated in synthetic and natural water samples. The results showed that the toxicity of nano-ZnO to E. coli depended on not only free Zn2+ but also the coexisting cations which could reduce the toxicity of Zn2+. Increasing solution pH, HPO42−, and DOM reduced the concentration of free Zn2+ released from nano-ZnO, and thus lowered the toxicity of nano-ZnO. In addition, both Ca2+ and Mg2+ dramatically reduced the toxicity of Zn2+ to E. coli. These results highlight the importance of water chemistry on the toxicity evaluation of nano-ZnO in natural waters.

We employed stable isotope probing (SIP) with 13C-labeled hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) to identify active microorganisms responsible for RDX biodegradation in groundwater microcosms. Sixteen different 16S rRNA gene sequences were derived from microcosms receiving 13C-labeled RDX, suggesting the presence of microorganisms able to incorporate carbon from RDX or its breakdown products. The clones, residing in Bacteroidia, Clostridia, α-, β- and δ-Proteobacteria, and Spirochaetes, were different from previously described RDX degraders. A parallel set of microcosms was amended with cheese whey and RDX to evaluate the influence of this co-substrate on the RDX-degrading microbial community. Cheese whey stimulated RDX biotransformation, altered the types of RDX-degrading bacteria, and decreased microbial community diversity. Results of this study suggest that RDX-degrading microorganisms in groundwater are more phylogenetically diverse than what has been inferred from studies with RDX-degrading isolates.

Maternal transfer of mercury in fish represents a potential route of elimination for adult females and a risk to developing embryos. To better quantify maternal transfer, we measured Hg in female largemouth bass (Micropterus salmoides) muscle and eggs from six waterbodies. Mercury in eggs from two waterbodies exceeded a US federal screening level (0.3 μg g−1) and was likely high enough to cause adverse reproductive effects. We found a curvilinear relationship between female and egg Hg. Fish with <0.37 μg g−1 Hg had low levels of Hg in eggs; those with Hg >0.37 μg g−1 showed a direct relationship between egg and muscle Hg (Log10 egg Hg = −1.03 + 1.18 * log10 muscle tissue Hg + 2.15 * (log10 muscle tissue Hg + 0.35)2). We also report higher maternal transfer (0.2–13.2%) and higher ratios of egg to muscle tissue Hg (4–52%) and egg to whole body Hg concentrations (7–116%) than previously observed for teleost fish.

Studies have shown that socioeconomic and environmental factors have direct/indirect influences on TB. This research focuses on TB prevalence of Hong Kong in relation to its compact urban development comprising of high-rise and high-density residential dwellings caused by rapid population growth and limited land resources. It has been postulated that occupants living on higher levels of a building would benefit from better ventilation and direct sunlight and thus less likely to contract infectious respiratory diseases. On the contrary, those on lower floors amid the dense clusters of high-rises are more susceptible to TB infection because of poorer air quality from street-level pollution and lesser exposure to direct sunlight. However, there have not been published studies to support these claims. As TB continues to threaten public health in Hong Kong, this study seeks to understand the effects of housing development on TB occurrences in an urban setting.

The presence of pyrethroids in both urban and agricultural sediments at levels lethal to invertebrates has been well documented. However, variations in bioavailability among sediments make accurate predictions of toxicity based on whole sediment concentrations difficult. A proposed solution to this problem is the use of bioavailability-based estimates, such as solid phase microextraction (SPME) fibers and Tenax beads. This study compared three methods to assess the bioavailability and ultimately toxicity of pyrethroid pesticides including field-deployed SPME fibers, laboratory-exposed SPME fibers, and a 24-h Tenax extraction. The objective of the current study was to compare the ability of these methods to quantify the bioavailable fraction of pyrethroids in contaminated field sediments that were toxic to benthic invertebrates. In general, Tenax proved a more sensitive method than SPME fibers and a correlation between Tenax extractable concentrations and mortality was observed.

The Air Quality Standards for Particulate Matter (PM) at high altitude urban areas in different countries, must consider the pressure and temperature due to the effect that these parameters have on the breath volume.This paper shows the importance to correct Air Quality Standards for PM considering pressure and temperature at different altitudes. Specific factors were suggested to convert the information concerning PM, from local to standard conditions, and adjust the Air Quality Standards for different high altitudes cities. The correction factors ranged from: 1.03 for Santiago de Chile to 1.47 for El Alto Bolivia. Other cities in this study include: Mexico City, México; La Paz, Bolivia; Bogota, Cali and Medellin, Colombia; Quito, Ecuador and Cuzco, Peru.If these corrections are not considered, the atmospheric concentrations will be underestimated.

Atmospheric concentration of Polychlorinated biphenyls (PCBs) were measured on diurnal basis by active air sampling during Dec 2006 to Feb 2007 in seven major cities from the northern (New Delhi and Agra), eastern (Kolkata), western (Mumbai and Goa) and southern (Chennai and Bangalore) parts of India. Average concentration of Σ25PCBs in the Indian atmosphere was 4460 (±2200) pg/m−3 with a dominance of congeners with 4–7 chlorine atoms. Model results (HYSPLIT, FLEXPART) indicate that the source areas are likely confined to local or regional proximity. Results from the FLEXPART model show that existing emission inventories cannot explain the high concentrations observed for PCB-28. Electronic waste, ship breaking activities and dumped solid waste are attributed as the possible sources of PCBs in India. Σ25PCB concentrations for each city showed significant linear correlation with Toxicity equivalence (TEQ) and Neurotoxic equivalence (NEQ) values.

This study examined the temporal and spatial trends in wet deposition of 19 legacy and emerging brominated flame retardants (14 polybrominated diphenyl ethers (PBDEs), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), decabromodiphenylethane (DBDPE), hexabromocyclododecane (HBCD) and pentabromoethylbenzene (PBEB)) at 9 sites in the Canadian Great Lakes between 2004 and 2010. Concentrations of BDE-209 in wet deposition declined significantly. This indicates that the voluntary actions taken to phase out the use of BDE 209 in North America are having an immediate effect on its environment concentrations. The analysis also revealed the presence of 22 short-term high concentration events that dominated overall wet deposition loadings of current-use BFRs to the lakes. For instance, one sample in 2007 was responsible for 37% of the total loadings of HBCD to Lake Huron over the entire six-year sampling period. This questions the current paradigm of how we believe such pollutants enter the environment.

Increasing metal pollution has drawn broad public attention in China due to severe environmental quality deterioration. However, so far, there has been no study to survey metal accumulation in Chinese farmland soil at the national scale. In this study, we determined 11 metals in farmland soils across the Mainland China. Our results indicated the concentrations of Pb, Cd, Zn, and Cu (10.1–184.2, 0.082–1.31, 20.2–321.9, 8.2–515.9 mg/kg, respectively) were elevated above their reference values. Moreover, these metals followed a similar geochemical distribution pattern. The accumulation of Pb, Cd, Zn, and Cu in soils may be associated with human activities for soil fertility. Cadmium had the highest pollution index (PI) of 5.28, and the average hazard quotients (HQs) for all the metals were below 1. Hence, except for Cd, the metals in Chinese arable soils are comparatively safe. Results from this study may provide valuable information for agricultural soil management in China.