The immune system can be the target of many chemicals, with potentially severe adverse effects on the host’s health. In the literature, carbamate (CM) pesticides have been implicated in the increasing prevalence of diseases associated with alterations of the immune response, such as hypersensitivity reactions, some autoimmune diseases and cancers. CMs may initiate, facilitate, or exacerbate pathological immune processes, resulting in immunotoxicity by induction of mutations in genes coding for immunoregulatory factors and modifying immune tolerance. In the present study, direct immunotoxicity, endocrine disruption and inhibition of esterases activities have been introduced as the main mechanisms of CMs-induced immune dysregulation. Moreover, the evidence on the relationship between CM pesticide exposure, dysregulation of the immune system and predisposition to different types of cancers, allergies, autoimmune and infectious diseases is criticized. In addition, in this review, we will discuss the relationship between immunotoxicity and cancer, and the advances made toward understanding the basis of cancer immune evasion.

This study was conducted to investigate the typical types of chemically enhanced backwash by-products (CEBBPs) produced in the chemically enhanced backwash (CEB) process and the influence of CEB parameters on typical CEBBPs in the coagulation–ultrafiltration process. Health risk assessment was applied to assess the potential adverse health effect from exposure to effluent after the optimal CEB. The results indicated that backwash reagent of sodium hypochlorite reacted with organic matter to produce CEBBPs, including 12 species of volatile halogenated organic compounds (VHOCs) and 9 species of haloacetic acids (HAAs) during CEB process. The amount of HAAs was higher than that of VHOCs indicating that the content of primary HAA precursor (hydrophilic organic matter) was high in raw surface water and the coagulation process could not lower the hydrophilic organic matter concentration. After comprehensive consideration of the influence of single factors on the CEBBP formation and membrane cleaning effect, the optimal CEB parameters was 4 min of backwash duration, 120 min of backwash interval, 20 L/(m²·h) of backwash flux, and 25 mg/L of reagent concentration. Under the optimum CEB cleaning parameters, the effluent did not pose non-carcinogenic risk to local residents but could pose potential carcinogenic risk.

Benthic algae or microphytobenthos (MPB) in intertidal flats play an important role in the sediment and overlying water ecosystems. We hypothesize that there are effects of sediment texture on the vertical distribution of MPB using chlorophyll a (chl a) as a proxy for MPB biomass and present results over a 2.5-year period. Four sites were sampled monthly: two sandy sites (A10 and A12) and two muddy sites (A0 and A14) on the intertidal flats of the Fraser River Estuary. At the two sandy sites, pigments were distributed down to 10 cm. High ratios of depth-integrated chl a to phaeopigments suggest that the chl a had been recently buried. In contrast, at the muddy sites, pigments were limited to the top 4 cm, with MBP in the top 1 cm contributing up to 60 % of the whole sediment core pigments. As a result, the depth-integrated chl a values were on average 2,044 mg m–² (160–4,200) at A10 and 882 mg m⁻² (183–2,569) at A12, the two sandy sites, and much higher than at the two muddy sites where averages of 84 mg m⁻² (41–174) and 235 mg m⁻² (77–854) were measured at A0 and A14, respectively. Despite these lower concentrations at the muddy sites than at the sandy sites, particulate organic carbon (POC) and nitrogen (PON) concentrations showed a homogenous vertical distribution at the two sandy sites. Such a homogeneous vertical distribution of chl a, POC, and PON suggests that vertical transport mechanisms were actively transporting organic material into and out of the sediment. These results suggest that MBP on sandy sediments play a very active role in providing food for herbivores and are interacting with the overlying water column in the sediment-water exchange processes during tidal cycles.

The pesticide risk analysis process is well regulated in the EU, especially in relation to placing on the market authorisation procedures, but in order to avoid risks for human health and environment in the use phase, information on how these substances are employed and on socio-behavioural factors that can influence the exposure have to be taken into account. To better explore reasons about the gap between risk assessment and risk management, within the EU FP7 Health and Environmental Risks: Organisation, Integration and Cross-fertilisation of Scientific Knowledge (HEROIC) project, a stepwise stakeholder’s consultation process was developed using a mixed approach in two different phases (survey and roundtable). We elicited stakeholder views regarding factors that could limit the pesticide risk assessment phase linked on how the knowledge is produced and the way the data are used in risk management and in risk communication, also taking into account qualitative factors such as responsibility, trust and behaviours, which could have impact on risk assessment policies. Activities deployed indicate that some changes and interaction are needed to better define the problems at the formulation stage, and the type of information risk assessor has to provide, to better inform risk manager in addressing different societal needs, to strengthen the credibility of the process of risk assessment and improve the effectiveness of policies. Integrations between disciplines may initially increase the complexity but in turn will provide a better and more useful estimation of the risk, reinforce transparency and drive a more efficient use of risk management resources.

The radiation contamination after the Fukushima Daiichi Nuclear Power Plant accident attracts considerable concern all over the world. Many countries, areas, and oceans are greatly affected by the emergency situation other than Japan. An effective remediation strategy is in a highly urgent demand. Though plenty of works have been carried out, progressive achievements have not yet been well summarized. Here, we review the recent advances on the remediation of radiocesium-contaminated liquid waste, soil, and ash. The overview of the radiation contamination is firstly given. Afterwards, the current remediation strategies are critically reviewed in terms of the environmental medium. Special attentions are paid on the adsorption/ion exchange and electrically switched ion exchange methods. Finally, the present review outlines the possible works to do for the large-scale application of the novel remediation strategies.

The effect of insecticides (acephate and imidacloprid) on a freshwater microalga Chlamydomonas mexicana was investigated with respect to photosynthetic pigments, carbohydrate and protein contents, fatty acids composition and induction of stress indicators including proline, superoxide dismutase (SOD) and catalase (CAT). C. mexicana was cultivated with 1, 5, 10, 15, 20 and 25 mg L⁻¹ of acephate and imidacloprid. The microalga growth increased with increasing concentrations of both insecticides up to 15 mg L⁻¹, beyond which the growth declined compared to control condition (without insecticides). C. mexicana cultivated with 15 mg L⁻¹ of both insecticides for 12 days was used for further analysis. The accumulation of photosynthetic pigments (chlorophyll and carotenoids), carbohydrates and protein was decreased in the presence of both insecticides. Acephate and imidacloprid induced the activities of superoxide dismutase (SOD) and catalase (CAT) and increased the concentration of proline in the microalga, which play a defensive role against various environmental stresses. Fatty acid analysis revealed that the fraction of polyunsaturated fatty acids decreased on exposure to both insecticides. C. mexicana also promoted 25 and 21 % removal of acephate and imidacloprid, respectively. The biochemical changes in C. mexicana on exposure to acephate and imidacloprid indicate that the microalga undergoes an adaptive change in response to the insecticide-induced oxidative stress.

In order to promote the risk-based strategy in the investigation, assessment, and remediation of Chinese brownfield sites, the Health and Environmental Risk Assessment (HERA) software was developed. It is vital to validate the HERA model and compare the inter-model differences of HERA model against other available risk assessment tools. This paper discusses the similarities and differences between the Risk-Based Corrective Action (RBCA) Tool Kit and the HERA model by evaluating the health risk of organic contaminated groundwater sources for a chemical works in China for the first time. Consequently, the HERA and RBCA models yielded the identical results for Site-Specific Assessment Criteria (SSAC) under the commercial redevelopment. However, the HERA estimated more conservative and stringent SSACs under the residential scenario based on the different exposure calculations. The inhalation of indoor vapors was the most predominated exposure pathway for all the volatile organic compounds (VOCs) determined using the RBCA and HERA models. According to the HERA model, inhalation of chloroform may cause the highest unacceptable carcinogenic risk at 2.31 × 10⁻³ under the residential scenario. Therefore, it is recommended that a risk-based remedial strategy be developed to ensure the safe and sustainable redevelopment of the site.

This study investigates PCBs attenuation and the abundance of active polychlorinated-degrading Dehalococcoides spp. biphenyl dioxygenase (bphC), chemotaxis (CheA), and flagellum (flic) genes in floody and dry soil conditions polluted with polychlorinated biphenyls. The results revealed that total PCBs, high chlorinated PCBs (>4 cl), and less chlorinated PCBs (<4 cl) decreased with the passage of time in floody and dry soil conditions. The reduction of total PCBs (13.87 %) and less chlorinated PCBs (15.39 %) was more in dry soil than floody soil, while high chlorinated PCBs showed more reduction in floody soil (8.06 %) than dry soil. Dehaloccoides spp., bphC, CheA, and flic genes indicated temporal dynamics in abundance in floody and dry soil conditions. The highest abundance was 1.6 × 10⁹, 3.7 × 10⁴, and 3.6 × 10² copies in floody and 1.6 × 10⁴ copies in dry soil for Dehalococcoides spp., bphC, CheA, and flic, respectively. Multivariate statistics (RDA) revealed that Dehaloccoides spp. were positively influenced by the higher chlorinated PCBs and soil physical properties, CheA gene with floody soil, flic gene with total PCBs and less chlorinated PCBs, and bphC gene was affected with moisture contents and less chlorinated PCBs. This study provides new insight in the attenuation of PCBs and the abundance of active Dehalococcoides spp. and genes in PCBs polluted soil under floody and dry soil conditions.

Generation of secondary sludge is a major concern of textile dye removal by coagulation process. Combinatorial coagulation-biodegradation treatment system has been found efficient in degradation of coagulated textile dye sludge. Moringa oleifera seed powder (700 mg L⁻¹) was able to coagulate textile dyestuff from real textile wastewater with 98 % color removal. Novel consortium-BBA was found to decolorize coagulated dye sludge. Parameters that significantly affect coagulation process were optimized using response surface methodology. The bench-scale stirred tank reactor (50-L capacity) designed with optimized parameters for coagulation process could efficiently remove 98, 89, 78, and 67 % of American Dye Manufacturer’s Institute (ADMI) in four repetitive cycles, respectively. Solid-state fermentation composting reactor designed to treat coagulated dye sludge showed 96 % removal of dye within 10 days. Coagulation of dyes from textile wastewater and degradation of coagulated dye sludge were confirmed by Fourier transform infrared spectroscopy (FTIR) analysis. Cell morphology assay, comet assay, and phytotoxicity confirmed the formation of less toxic products after coagulation and degradation mechanism.

Batch adsorption experiments were performed for the removal of chromium (III) and chromium (VI) ions from aqueous solutions using Canadian peat and coconut fiber. The Langmuir model was used to describe the adsorption isotherm. The maximum adsorption for peat reached 18.75 mg/g for Cr(III) and 8.02 mg/g for Cr(VI), whereas the value for fiber was slightly higher and reached 19.21 mg/g for Cr(III) and 9.54 mg/g for Cr(VI). Both chromium forms could be easily eluted from the materials. The adsorption of chromium forms to organic matter could be explained in terms of formation of donor-acceptor chemical covalent bound with hydroxyl groups as ligands and chromium as the central atom in the formed complex. The chromate-reducing activities were monitored with the use of electron paramagnetic resonance spectroscopy. The results showed that both adsorption and reduction occurred simultaneously and the maximum adsorption capacity of hexavalent chromium being equal to 95 % for fiber and 92 % for peat was obtained at pH 1.5. The reduction of Cr(VI) in wastewaters began immediately and disappeared after 20 h. Both materials contained yeast and fungi species which can be responsible for reduction of chromium compounds, due to their enzymatic activity (Chwastowski and Koloczek (Acta Biochim Pol 60: 829–834, 2013)). The reduction of Cr(VI) is a two-phase process, the first phase being rapid and based on chemical reaction and the second phase having biological features. After the recovery step, both types of organic materials can be used again for chromium adsorption without any loss in the metal uptake. Both of the materials could be used as biofilters in the wastewater treatment plants.