House dust has been recognized as an important contributor to Pb exposure of children. Here we conducted a comprehensive study to investigate geographical variation of Pb in Chinese villager house dust. The influences of outdoor soil Pb concentrations, dates of construction, house decoration materials, heating types, and site specific pollution on Pb concentrations in house dust were evaluated. The concentrations of Pb in 477 house dust samples collected from twenty eight areas throughout China varied from 12 to 2510 mg/kg, with a median concentration of 42 mg/kg. The median Pb concentrations in different geographical areas ranged from 16 (Zhangjiakou, Hebei) to 195 mg/kg (Loudi, Hunan). No correlations were found between the house dust Pb concentrations and the age of houses, as well as house decoration materials. Whereas outdoor soil, coal combustion, and site specific pollution may be potential Pb sources. Principal component analysis (PCA) confirmed that elemental compositions of the house dust were controlled by both anthropogenic and geogenic sources. Using scanning electron microscopy (SEM), the Pb bearing particles in the house dust were also studied.

The Clinch and Powell Rivers (Virginia, USA) support diverse mussel assemblages. Extensive coal mining occurs in both watersheds. In large reaches of both rivers, major ion concentrations are elevated and mussels have been extirpated or are declining. We conducted a laboratory study to assess major ion effects on growth and survival of juvenile Villosa iris. Mussels were exposed to pond water and diluted pond water with environmentally relevant major ion mixtures for 55 days. Two treatments were tested to mimic low-flow concentrations of Ca2+, Mg2+, SO42−, HCO3+, K+ and Cl− in the Clinch and Powell Rivers, total ion concentrations of 419 mg/L and 942 mg/L, respectively. Mussel survival (>90%) and growth in the two treatments showed little variation, and were not significantly different than in diluted pond water (control). Results suggest that major ion chronic toxicity is not the primary cause for mussel declines in the Clinch and Powell Rivers.

Samples of 474 forest stands in Germany were analysed for concentrations of polycyclic aromatic hydrocarbons (PAHs) in three sampling depths. Enhanced concentrations were mainly found at spots relatively close to densely industrialized and urbanized regions and at some topographically elevated areas. Average enrichment factors between mineral soil and humic layer depend on humus type i.e. decrease from mull via moder to mor. Based on their compound-patterns, the observed samples could be assigned to three main clusters. For some parts of our study area a uniform assignment of samples to clusters over larger regions could be identified. For instance, samples taken at vicinity to brown-coal strip-mining districts are characterized by high relative abundances of low-molecular-weight PAHs. These results suggest that PAHs are more likely originated from local and regional emitters rather than from long-range transport and that specific source-regions can be identified based on PAH fingerprints.

The mission of protected areas is to conserve biodiversity and improve human welfare. To assess the effect of urban waters entering into protected areas, we performed 48-h whole-effluent exposures with fathead minnows, analyzing changes in steady state levels of mRNAs in the livers of exposed fish. Raw wastewater, treated city wastewater, and treated wastewater from a university were collected for exposures. All exposed fish showed altered mRNA levels of DNA damage-repair genes. Fish exposed to raw and treated wastewaters showed down-regulation of transcripts for key intermediates of cholesterol biosynthesis and elevated plasma cholesterol. The type of wastewater treatment influenced the response of gene transcription. Because of the relevance of some of the altered cellular pathways, we suggest that these effluents may cause deleterious effects on fish inside protected areas that receive these waters. Inclusion of research and mitigation efforts for this type of threat in protected areas management is advised.

Ground-level ozone (O3) pollution has become one of the top environmental issues in China, especially in those economically vibrant and densely populated regions. In this paper, we reviewed studies on the O3 concentration observation and O3 effects on food crops throughout China. Data from 118 O3 monitoring sites reported in the literature show that the variability of O3 concentration is a function of geographic location. The impacts of O3 on food crops (wheat and rice) were studied at five sites, equipped with Open Top Chamber or O3-FACE (free-air O3 concentration enrichment) system. Based on exposure concentration and stomatal O3 flux–response relationships obtained from the O3-FACE experimental results in China, we found that throughout China current and future O3 levels induce wheat yield loss by 6.4–14.9% and 14.8–23.0% respectively. Some policies to reduce ozone pollution and impacts are suggested.

Microplastics (MP) are ubiquitous contaminants able to cause adverse effects on organisms. Three hypotheses were tested here: early Pomatoschistus microps juveniles can ingest MP; the presence of MP may reduce fish predatory performance and efficiency; developmental conditions may influence the prey selection capability of fish. Predatory bioassays were carried out with juveniles from two estuaries with differences in environmental conditions: Minho (M-est) and Lima (L-est) Rivers (NW Iberian coast). Polyethylene MP spheres (3 types) alone and in combination with Artemia nauplii were offered as prey. All the MP types were ingested, suggesting confusion with food. Under simultaneous exposure to MP and Artemia, L-est fish showed a significant reduction of the predatory performance (65%) and efficiency (up to 50%), while M-est fish did not, suggesting that developmental conditions may influence the prey selection capability of fish. The MP-induced reduction of food intake may decrease individual and population fitness.

Although iron (Fe) plaque has been shown to significantly affect the uptake of toxic antimony (Sb) by rice, knowledge about the influence of iron plaque on antimony (Sb) (amount, mechanisms, etc) is, however, limited. Here, the effect of Fe plaque on Sb(III) and Sb(V) (nominal oxidation states) uptake by rice (Oryza sativa L.) was investigated using hydroponic experiments and synchrotron-based techniques. The results showed that iron plaque immobilized Sb on the surface of rice roots. Although the binding capacity of iron plaque for Sb(III) was markedly greater than that for Sb(V), significantly more Sb(III) was taken up by roots and transported to shoots. In the presence of Fe plaque, Sb uptake into rice roots was significantly reduced, especially for Sb(III). However, this did not translate into decreasing Sb concentrations in rice shoots and even increased shoot Sb concentrations during high Fe–Sb(III) treatment.

Sewage impacted soil, sludge and water samples were studied to understand the occurrence and formation of thiosteranes and to determine the relevance of these compounds as tracers for sewage input into the environment. Soils were collected from wastewater irrigation fields (Wroclaw, Poland), water from the Nexapa River Basin (Mexico), which also received wastewater and wastewater treatment plant (WWTP) effluent, and water and sludge from the Norman WWTP (USA) at different treatment stages. Thiosteranes represented a high proportion of the steroid fraction in the Wroclaw irrigation field and the Nexapa River Basin samples. Small amounts of thiosteranes were found in anaerobically digested sludge from the Norman WWTP. A good correlation between coprostanone and thiosterane concentrations suggests thiosteranes were produced by stanone sulphurization under anoxic conditions. Thiosterane stability under anoxic and suboxic conditions indicates their potential use as tracers for environmental input of sewage products or land application of sewage sludge.