Background, aim, and scope In the 50 years or so that polychlorinated biphenyls (PCBs) were manufactured in the USA and elsewhere, they were widely used in numerous applications because of their desirable properties. The purpose of this paper is to review and summarize in one place the factual information about the uses of PCBs, as well as to correct some misconceptions that have arisen over the years. The focus is on applications in the USA for which there is ample documentation. However, use patterns were probably similar worldwide. Materials and methods Review. Results PCBs were used primarily as electrical insulating fluids in capacitors and transformers and also as hydraulic, heat transfer, and lubricating fluids. PCBs were blended with other chemicals as plasticizers and fire retardants and used in a range of products including caulks, adhesives, plastics, and carbonless copy paper. In the USA, PCBs were manufactured from 1929 through mid-1977, although many products remained in service for decades after the manufacture of PCBs was terminated. This article reviews the historic uses of PCBs in the USA and discusses, where possible, the relative sales volumes. Especially with smaller volume, military, and third-party uses, documenting a use and/or differentiating between a commercial use and an experimental test batch is not possible. Discussion A major contribution of this paper is to differentiate reported commercial applications of PCBs that can be documented from those which cannot. Undocumented uses may include actual minor uses as well as reported applications that are unlikely ever to have been commercialized.

PURPOSE: We tested the genetic diversity in wild mice (Mus musculus domesticus) inhabiting the asbestos-polluted area as a model for the long-term mutagenic effect of asbestos. Hazardous effects of deposited asbestos persist in the environment because of low rate of fiber disintegration. The upper layers of the soil in the vicinity of a former asbestos factory are nearly “saturated” with asbestos fibers and dust. Natural populations of mice dwell in this area and are constantly exposed to asbestos fibers. METHODS: We measured the microsatellites genetic diversity of wild mice (Mus musculus domesticus) inhabiting the asbestos-polluted area as a model for the long-term mutagenic effect of this environmental toxin. RESULTS: The six tested microsatellites were highly polymorphic, revealing 111 different alleles for the two sampled populations. Effective number of alleles was slightly higher in the polluted population relative to the control population, while observed heterozygosity was lower. The chromatographic profile of the polluted population exhibited a significantly higher number of bands, probably resulting from somatic mutations, in addition to the ordinary microsatellite band profiles. CONCLUSIONS: Long-term exposure to asbestos fibers significantly elevates the level of somatic mutations. It also leads to a relatively high level of observed homozygosity, a phenomenon that may be associated with loss of heterozygosity. Based on the mice population, our data suggest elevated health risks for humans living in an asbestos-polluted area.

BACKGROUND: In this review, the position of behavioural ecotoxicology within the available means to assess the status of marine environments is described as filling the gap for the needed “early warning” signals. A few examples of studies performed since the 1960s are discussed to highlight the sensitivity of these approaches in investigating the effects of chemicals, including priority pollutants and emerging contaminants, relative to conventional toxicity tests measuring survival. DISCUSSION: The advantage of the behavioural response is due to the integration of biochemical and physiological processes that reflect changes at higher levels of organisation with ecological relevance. Avoidance often represents a behavioural symptom easily detected in many animals exposed to contaminants and would be a useful test to explore more widely. This rapid response would reflect a defence mechanism protective against further exposure and the potential development of more pronounced deleterious effects, whilst in some cases, escape could lead to the relocation of a species with negative consequences. An investigation of the avoidance behaviour of mud shrimp, Corophium volutator, along with the chemical analyses of sediments and amphipods to assess the quality of harbour sediments is summarised. The body burden of the amphipods was 1,000 times lower than the one associated with narcosis, emphasizing the sensitivity of this endpoint. The application of this acute toxicity test is briefly compared to additional work that involved intertidal mussels collected in the field. CONCLUSIONS: Recent research undertaken with mud snails, Ilyanassa obsoleta, and harbour sediments confirmed the usefulness of the escape behaviour as an assessment tool. However, the limits of the state of knowledge regarding the fate of contaminants in species with the ability to metabolise contaminants is further discussed along with directions to be pursued to address questions arising from the reviewed literature.

BACKGROUND, AIM, AND SCOPE: Although highly diverse and specialized prokaryotic and eukaryotic microbial communities in soil degrade polycyclic aromatic hydrocarbons (PAHs), most of these are removed slowly. This review will discuss the biotechnological possibilities to increase the microbial dissipation of PAHs from soil as well as the main biological and biotechnological challenges. DISCUSSION AND CONCLUSIONS: Microorganism provides effective and economically feasible solutions for soil cleanup and restoration. However, when the PAHs contamination is greater than the microbial ability to dissipate them, then applying genetically modified microorganisms might help to remove the contaminant. Nevertheless, it is necessary to have a more holistic review of the different individual reactions that are simultaneously taking place in a microbial cell and of the interactions microorganism–microorganism, microorganism–plant, microorganism–soil, and microorganisms–PAHs. PERSPECTIVES: Elucidating the function of genes from the PAHs-polluted soil and the study in pure cultures of isolated PAHs-degrading organisms as well as the generation of microorganisms in the laboratory that will accelerate the dissipation of PAHs and their safe application in situ have not been studied extensively. There is a latent environmental risk when genetically engineered microorganisms are used to remediate PAHs-contaminated soil.

PURPOSE: This work was planned for providing a useful screening tool for the selection of Populus alba clones suitable for phytoremediation techniques. To this aim, we investigated variation in arsenic, cadmium, copper, and zinc tolerance, accumulation and translocation in three poplar clones through an in vitro screening. Poplars have been widely proposed for phytoremediation, as they are adaptable to grow on contaminated areas and able to accumulate metals. The investigation of possible differences among poplar clones in metal tolerance and accumulation deserves to be deeply studied and exploited for the selection of the more suitable tool for phytoremediation purposes. METHODS: In vitro multiplied microshoots of a commercial and two autochthonous P. alba clones were subcultured on hormone-free WPM medium for 1 month and then transferred for 2 weeks onto media containing different concentrations of the metals investigated. At the end of the treatments, plantlets were sampled, weighed, and mineralised by wet ashing. Metal concentrations were determined by ICP-OES. RESULTS: For the metal concentration used in the experiments, our clones of P. alba showed variation in metal tolerance, metal accumulation and content. The fast-growing commercial clone, even if rarely showing the highest plant metal concentration, displayed the highest metal content, suggesting biomass production as the key factor in evaluating the phytoextraction capacity of P. alba clones for the metals studied. CONCLUSIONS: Data demonstrated that in vitro screening of cuttings represents a valuable way of assessing the ability of different poplar clones to take up, tolerate and survive metal stress.

PURPOSE: This study aims at evaluating (a) whether concentrations of a suite of elements in mosses sampled in the arctic region around Zackenberg reflect background concentrations useful for estimating pollution levels in industrialized parts of the northern hemisphere as is attempted, e.g. in the framework of the UNECE ICP Vegetation monitoring programme, and (b) whether there are any influences from Zackenberg research station detectable in these concentrations. METHODS: Two moss species were sampled according to guidelines used in the UNECE ICP Vegetation programme. Samples were analysed for ¹⁹⁵Pt at low resolution, ²⁷Al, ⁵²Cr, ⁶⁵Cu, ⁶⁶Zn, ⁹⁵Mo, ¹¹¹Cd, ¹¹⁸Sn, ¹²¹Sb and ²⁰⁸Pb at medium resolution and ⁷⁵As at high resolution on an Element 2 inductively coupled plasma sector field mass spectrometer. RESULTS: Except for Al, As and Cr, data from Zackenberg showed significantly lower mean element concentrations than those reported in comparable studies from all over the world including those from other Arctic environments. Minimum concentrations in Zackenberg mosses were consistently below all values reported so far for all elements analysed. The results of a PCA suggested only a slight impact from Zackenberg research station on concentrations of Cd, Mo and Zn in moss. CONCLUSIONS: We conclude that the sites in Zackenberg can be considered true background sites providing baseline concentrations of at least eight elements for comparable monitoring studies.

BACKGROUND AND PURPOSE: More and more coal-fired power plants equipped with seawater flue gas desulfurization systems have been built in coastal areas. They release large amount of mercury (Hg)-containing waste seawater into the adjacent seas. However, very limited impact studies have been carried out. Our research targeted the distribution of Hg in the seawater, sediment, biota, and atmosphere, and its environmental transportation. METHODS: Seawater samples were collected from five sites: 1, sea areas adjacent to the power plant; 2, near discharge outlets; 3, the aeration pool of the power plant; and 4 and 5, two reference sites. The total gaseous Hg was determined in situ with a Tekran 2537B. Analyses of total Hg (TM) followed the USEPA methods. RESULTS: In most part of the study area, TM concentrations were close to the reference values and Hg transfer from the seawater into the sediment and biota was not obvious. However, in the aeration pool and near the waste discharge outlets, atmospheric and surface seawater concentrations of TM were much higher, compared with those at a reference site. The concentration ranges of total gaseous Hg and TM in seawater were 3.83–8.60 ng/m3 and 79.0–198 ng/L near the discharge outlets, 7.23–13.5 ng/m3 and 186–616 ng/L in the aeration pool, and 2.98–4.06 ng/m3 and 0.47–1.87 ng/L at a reference point. CONCLUSIONS: This study suggested that the Hg in the flue gas desulfurization waste seawater was not only transported and diluted with sea currents, but also could possibly be transferred into the atmosphere from the aeration pool and from the discharge outlets.

Background, aim and scope Pollutants always co-exist in the environment. Determining and characterizing the interaction among chemicals is an important issue. Experimental designs (ED) play an important role in evaluating the interactions. The main aim of our study is to provide the test and analysis of the toxicity interaction with a novel ED method. Materials and methods A novel direct equipartition ray design (EquRay) procedure was proposed to effectively and systematically determine the toxicities of binary mixtures on Vibrio qinghaiensis sp.-Q67. Here, one component is ionic liquid, 1-butyl-2,3-dimethylimidazolium chloride (IL1), 1-butylpyridinium bromide (IL2) or N-hexylpyridinium bis(trifluoromethylsulfonyl)imide (IL3), and another is dichlorvos (DIC). The toxicity interaction was evaluated by comparing experiment and additive model together with three-dimension deviation response surface (DRS) analysis. Result Selecting CA as a reference model, the binary mixtures exerted less than additive (antagonism). Most of the deviations occurred in the centre portion of the DRS where the dCA (deviation from CA) values are between −15% and −26% for IL1-DIC and IL2-DIC mixtures and −10% and −15% for IL3 and DIC. Selecting IA as a additive model, IL1-DIC and IL2-DIC mixtures exhibited less than additive (antagonism) while IL3-DIC displayed an addition action and the absolute values of dIAs (deviation from IA) were less than 10%. Conclusion A novel EquRay procedure was developed in this study and the EquRay can provide us with the information about the toxicity interaction between binary mixture components (such as DIC and IL) in different concentration regions across different mixture ratios.

Purpose The purpose of this paper is to determine the activity concentrations of radionuclide ¹³⁷Cs in soil samples on the territory of Belgrade and the province of Vojvodina. Also, the lifetime cancer mortality risk from external exposure during 1 year is assessed, and the effective dose is estimated. Methods Eighty eight soil samples were collected from 30 uncultivated locations in Belgrade, and 30 soil samples were collected from 10 locations in the province of Vojvodina. Activity concentrations were measured using an HPGe detector. Using dose conversion factors taken from “EPA Federal Guidance Report 12,” annual effective doses from external sources were estimated. The lifetime cancer mortality risk was assessed using cancer risk coefficients taken from “EPA Federal Guidance Report 13.” Results Activity concentrations of ¹³⁷Cs for the territory of Belgrade are in the range of 2.07-89.1 Bq/kg with a mean value of 23.77 Bq/kg; the estimated annual effective doses are in the range of 0.41-17.5 nSv with a mean value of 4.67 nSv, and assessed lifetime cancer mortality risks, normalized on 100,000 inhabitants, are in the range 0.2-9.5 × 10⁻⁵ with a mean value 2.5 × 10⁻⁵. Activity concentrations of ¹³⁷Cs for the province of Vojvodina are in the range of 2.73-18.9 Bq/kg with a mean value of 8.57 Bq/kg; estimated annual effective doses are in the range of 0.54-3.71 nSv with a mean value of 1.68 nSv, and assessed lifetime cancer mortality risks, normalized on 100,000 inhabitants, are in the range of 0.3-2.0 × 10⁻⁵ with a mean value 0.9 × 10⁻⁵. Conclusion Receiving doses are low from ¹³⁷Cs radionuclides occurring in soil, according to the linear no-threshold approach; the risk for cancer development exists but is very small.

Purpose The performance of nature reserves depends on the degree to which they represent a region's full biodiversity. Here, we conducted a study on Hainan Island, China, to assess how well Hainan's biodiversity features were captured by existing nature reserves. We also explored the driving forces behind the current protection pattern so as to provide guidelines for improving the island's conservation system. Methods We integrated the information on nature reserves, ecological variables, and human activities into a spatial database, then assessed the performance of nature reserves in representing natural variation, vegetation types, and species, and examined the impacts of human activities and land ownership on the current protection pattern. Results About 8.4% of Hainan Island was protected by nature reserves; the coverage was geographically biased toward its central mountainous areas with higher elevation, rugged terrain, and fertile soils. We found that 60% of the environmental units and 39.4% of the natural vegetation types had more than 10% of their area protected, respectively. Lowlands tended to have higher animal species richness, and the protection for endangered species was less efficient. Nature reserve coverage was negatively correlated with amount of converted habitats, human population density, and road density, and 82.4% of the total reserved area was allocated on state-owned land. Conclusions Nature reserve coverage was not enough to capture lowlands biodiversity features. The current protection pattern was significantly driven by several major conservation targets, human development, planning methods, and land ownership. To improve its conservation system, Hainan should enhance protection in the north and northeast plains and coastal regions, implement systematic planning approaches to define clear visions for guiding future conservation actions, and develop flexible management and funding mechanisms toward sustainable use of natural resources.