Batch and saturated soil column experiments were conducted to investigate sorption and mobility of two ¹⁴C-labeled contaminants, the hydrophobic chlordecone (CLD) and the sulfadiazine (SDZ), in the absence or presence of functionalized multi-walled carbon nanotubes (MWCNTs). The transport behaviors of CLD, SDZ, and MWCNTs were studied at environmentally relevant concentrations (0.1–10 mg L⁻¹) and they were applied in the column studies at different times. The breakthrough curves and retention profiles were simulated using a numerical model that accounted for the advective-dispersive transport of all compounds, attachment/detachment of MWCNTs, equilibrium and kinetic sorption of contaminants, and co-transport of contaminants with MWCNTs. The experimental results indicated that the presence of mobile MWCNTs facilitated remobilization of previously deposited CLD and its co-transport into deeper soil layers, while retained MWCNTs enhanced SDZ deposition in the topsoil layers due to the increased adsorption capacity of the soil. The modeling results then demonstrated that the mobility of engineered nanoparticles (ENPs) in the environment and the high affinity and entrapment of contaminants to ENPs were the main reasons for ENP-facilitated contaminant transport. On the other hand, immobile MWCNTs had a less significant impact on the contaminant transport, even though they were still able to enhance the adsorption capacity of the soil.

The use of road deicing salts in regions that experience cold winters is increasing the salinity of freshwater ecosystems, which threatens freshwater resources. Yet, the impacts of environmentally relevant road salt concentrations on freshwater organisms are not well understood, particularly in stream ecosystems where salinization is most severe. We tested the impacts of deicing salts—sodium chloride (NaCl), magnesium chloride (MgCl2), and calcium chloride (CaCl2)—on the growth and development of newly hatched rainbow trout (Oncorhynchus mykiss). We exposed rainbow trout to a wide range of environmentally relevant chloride concentrations (25, 230, 860, 1500, and 3000 mg Cl− L−1) over an ecologically relevant time period (25 d). We found that the deicing salts studied had distinct effects. MgCl2 did not affect rainbow trout growth at any concentration. NaCl had no effects at the lowest three concentrations, but rainbow trout length was reduced by 9% and mass by 27% at 3000 mg Cl− L−1. CaCl2 affected rainbow trout growth at 860 mg Cl− L−1 (5% reduced length; 16% reduced mass) and these effects became larger at higher concentrations (11% reduced length; 31% reduced mass). None of the deicing salts affected rainbow trout development. At sub-lethal and environmentally relevant concentrations, our results do not support the paradigm that MgCl2 is the most toxic deicing salt to fish, perhaps due to hydration effects on the Mg2+ cation. Our results do suggest different pathways for lethal and sub-lethal effects of road salts. Scaled to the population level, the reduced growth caused by NaCl and CaCl2 at critical early-life stages has the potential to negatively affect salmonid recruitment and population dynamics. Our findings have implications for environmental policy and management strategies that aim to reduce the impacts of salinization on freshwater organisms.

In freshwater settings the toxicity of the trace metal nickel (Ni) is relatively well understood. However, until recently, there was little knowledge regarding Ni toxicity in waters of higher salinity, where factors such as water chemistry and the physiology of estuarine and marine biota would be expected to alter toxicological impact. This review summarizes recent literature investigating Ni toxicity in marine and estuarine invertebrates and fish. As in freshwater, three main mechanisms of Ni toxicity exist: ionoregulatory impairment, inhibition of respiration, and promotion of oxidative stress. However, unlike in freshwater biota, where mechanisms of toxicity are largely Class-specific, the delineation of toxic mechanisms between different species is less defined. In general, despite changes in Ni speciation in marine waters, organism physiology appears to be the main driver of toxic impact, a fact that will need to be accounted for when adapting regulatory tools (such as bioavailability normalization) from freshwater to estuarine and marine environments.

Pyrethroids, a class of ubiquitous insecticides, have been considered as endocrine-disrupting chemicals (EDCs). Female animal studies suggested that early-life pyrethroids exposure might delay puberty onset. However, it remains unclear whether this association applies to human populations. A total of 305 girls at the ages of 9–15 years old were recruited in Hangzhou, China in this study. The concentration of the common metabolite of pyrethroids, 3-phenoxybenzoic acid (3-PBA), was analyzed in urine samples to reflect the exposure level of pyrethroids. The associations of 3-PBA with pubertal stages were evaluated using a multinomial logistic regression model. The geometric mean level of 3-PBA was 1.11 μg/L (1.42 μg/g for creatinine-adjusted concentration). There was a significant 45% reduction in odds of being in breast stage 3 (B3) per one-unit increase in the log-transformed 3-PBA levels [OR = 0.55 (95%CI: 0.31–0.98), p = 0.042]. A similar negative association was found between urinary 3-PBA levels with later onset by pubic hair stage 2 (P2) [OR = 0.56 (95%CI: 0.36–0.90), p = 0.015]. Similar negative association was also observed between urinary 3-PBA levels and pubertal onset indicated by menarche [OR = 0.51 (95%CI: 0.28–0.93), p = 0.029]. For the first time to our knowledge, this work reveals that pyrethroids exposure may increase the risk of delayed pubertal onset in girls.

Several epidemiological studies show the association between organophosphate pesticides (OPs) and the risk of non-Hodgkin lymphoma (NHL), yet various research results remain controversial. To explore the hazard of OPs exposure to human health, three kinds of OPs (Terbufos, Malathion, and Diazinon) that are non-halogenated aliphatic compounds were included in the meta-analysis. We searched PubMed and Web of Science Databases for articles published from 1985 to February 2017. The databases were also searched for eligible studies through a manual references search. The random-effect model was utilized to compute the odds ratios (ORs) and 95% confident intervals (CIs). A total of ten observational studies (five cohort, four case-control, and one nested case-control) were included in our meta-analysis, with a pooled OR of 1.22 (95% CI 1.04 to 1.43) of Malathion, Terbufos and Diazinion. The general heterogeneity for OR was moderate (Ph = 0.032, I² = 41.2%). The OR estimates in the subset analyses were utilized to compare the association between the three kinds of OPs and NHL; Terbufos (OR = 1.07, 95% CI 0.85 to 1.36) and Malathion (OR = 1.17, 95% CI 0.82 to 1.67) had a statistically non-significant relationship, whereas Diazinon (OR = 1.39, 95% CI 1.11 to 1.73) was significantly associated with an increased NHL risk. Because immune dysfunction was thought to increase NHL risk, the toxicity levels in the immune system of the three types of OPs were compared. Malathion attacked immune cells via a direct effect and Diazinon disrupted the neuro-immune system, which involves the cholinergic system of lymphocytes via indirect immune damage, whereas an immunotoxic effect involving Terbufos was not reported. Overall, the present meta-analysis indicated a statistically significant association between Diazinon exposure and NHL risk.

Lead (Pb) contaminated soils are a potential exposure hazard to the public. Amending soils with phosphorus (P) may reduce Pb soil hazards. Soil from Cleveland, OH containing 726 ± 14 mg Pb kg⁻¹ was amended in a laboratory study with bone meal and triple super phosphate (TSP) at 5:1 P:Pb molar ratios. Soil was acidified, neturalized and re-acidified to encourage Pb phosphate formation. PRSTM-probes were used to evaluate changes in soil solution chemistry. Soil acidification did not decrease in vitro bioaccessible (IVBA) Pb using either a pH 1.5, 0.4 M glycine solution or a pH 2.5 solution with organic acids. PRSTM-probe data found soluble Pb increased 10-fold in acidic conditions compared to circumnetural pH conditions. In acidic conditions (p = 3-4), TSP treated soils increased detected P 10-fold over untreated soils. Bone meal application did not increase PRSTM-probe detected P, indicating there may have been insufficient P to react with Pb. X-ray absorption spectroscopy suggested a 10% increase in pyromorphite formation for the TSP treated soil only. Treatments increased soil electrical conductivity above 16 mS cm⁻¹, potentially causing a new salinity hazard. This study used a novel approach by combining the human ingestion endpoint, PRSTM-probes, and X-ray absorption spectroscopy to evaluate treatment efficacy. PRSTM-probe data indicated potentially excess Ca relative to P across incubation steps that could have competed with Pb for soluble P. More research is needed to characterize soil solutions in Pb contaminated urban soils to identify where P treatments might be effective and when competing cations, such as Ca, Fe, and Zn may limit low rate P applications for treating Pb soils.

China has become the largest coal consumer and important emitter of trace metals in the world. A multiple-year inventory of atmospheric copper (Cu) and zinc (Zn) emissions from coal combustion in 30 provinces of China and 4 economic sectors (power plant, industry sector, residential sector, and others) for the period of 1995–2014 has been calculated. The results indicated that the total emissions of Cu and Zn increased from 5137.70 t and 11484.16 t in 1995–7099.24 t and 14536.61 t in 2014, at an annual average growth rate of 1.90% and 1.33%, respectively. The industrial sector ranked as the leading source, followed by power plants, the residential use, and other sectors. The emissions of Cu and Zn were predominantly concentrated in the northern and eastern regions of China due to the enormous consumption of coal by the industrial and the power sectors. The emissions of Cu and Zn were closely associated with mortality and life expectancy (LE) on the basis of multiple regression analysis. Spatial econometric models suggested that Cu and Zn emissions displayed significantly positive relevance with mortality, while they exhibited negative correlation with LE. The influence of the Cu emission peaked in the north of China for both mortality and LE, while the impacts of the Zn emission on mortality and LE reached a maximum value in Xinjiang Province. The results of the grey prediction model suggested that the Cu emission would decrease to 5424.73 t, whereas the Zn emissions could reach 17402.13 t in 2020. Analysis of more specific data are imperative in order to estimate the emissions of both metals, to assess their human health effects, and then to adopt effective measures to prevent environmental pollution.

Coasts of South China have experienced an unprecedented growth in its marine-caged fish industry. We analyzed mercury concentrations and stable mercury isotope ratios in fourteen fish species from two cage-cultured farms in Southern China. Total mercury concentrations of all species were lower than the human health screening values, but the human exposures through consumption of several carnivorous fish exceeded the USEPA's reference dose. Isotopic compositions in the sediment (δ202Hg: −1.45‰ to −1.23‰; Δ199Hg: −0.04‰ to –0.01‰) suggested that mercury in these farms were from coal combustion and industrial inputs. Commercial food pellets and fresh fish viscera provided the major sources of methylmercury to the farmed fish and dominated their mercury isotopic signatures. Non-carnivorous fish presented lower δ202Hg and Δ199Hg values than the carnivorous fish. Using a mixing model, we demonstrated that the majority of mercury in non-carnivorous species came from pellets and in carnivorous fish came from combined diets of pellets and viscera. Meanwhile, methylmercury concentrations and % methylmercury in the fish were positively correlated with δ202Hg values but not with Δ199Hg values, mainly because fish eating similar feeds maintained similar Δ199Hg values. Environmental influences of cage farming such as fish feces and uneaten viscera that continuously provide organic mercury to the environments need to be considered.

The aim of the study was to estimate the influence of the 2,4-dichlorophenoxy acetic acid and 2-methyl-4-chlorophenoxyacetic acid on the uptake and translocation of Cd, Co, Ni, Cu, Zn, Pb and Mn by wheat (Triticum aestivum L.). Two farmland soils typical for the central Polish rural environment were used. Studies involved soil analyses, contents of bioavailable, exchangeable and total forms for all investigated metals. Atomic absorption spectrometry was used to determine the concentration of the elements. The best correlation between the herbicide rate and the metal concentration was visibly for the underground part of plants. Analysis of variance proved that herbicide treatment of wheat frequently influences the metal transfer from soil and their concentration in roots and shoots. In particular, higher herbicide rates prompted the significant increase of all metals concentration in roots. Additionally, transfer coefficients depended on the type of soil and the herbicide rate applied. Uptake of metals may be also influenced by the formation of sparingly water-soluble metal-herbicide complexes. Its intensity would then depend on the solubility of particular chemical entity with the low solvable Pb, Cu and Cd complexes being the least mobile.

Vigorous air pollution control measures were implemented during the 2014 Asia-Pacific Economic Cooperation and a large-scale military parade (described here as “APEC Blue” and “Parade Blue” periods) in Beijing, China. A natural experiment was conducted in a health impact assessment framework to estimate the number of deaths attributable to PM2.5, using concentration-response functions derived from previous studies conducted in Beijing, combined with the differences in PM2.5 concentrations between intervention and reference periods. Substantial reductions in daily PM2.5 concentrations were observed during both intervention periods. Using the same dates from the prior year as a reference, daily PM2.5 concentration decreased from 98.57 μg/m³ to 47.53 μg/m³ during “APEC Blue”, and from 59.15 μg/m³ to 17.07 μg/m³ during the “Parade Blue”. We estimated that 39–63 all-cause deaths (21–51 cardiovascular, 6–13 respiratory deaths) have been prevented during the APEC period; and 41–65 deaths (22–52 cardiovascular, 6–13 respiratory deaths) have been prevented during the Parade period. This study shows that substantial mortality reductions could be achieved by implementing stringent air pollution mitigation measures.