This study investigates the occurrence of six phthalates and distribution of the three most-detected phthalates in the karst region of northern Puerto Rico (KRNPR) using data from historical records and current field measurements. Statistical data analyses, including ANOVA, Chi-Square, and logistic regression models are used to examine the major factors affecting the presence and concentrations of phthalates in the KRNPR. The most detected phthalates include DEHP, DBP, and DEP. At least one phthalate specie is detected above DL in 7% of the samples and 24% of the sampling sites. Concentrations of total phthalates average 5.08 ± 1.37 μg L−1, and range from 0.093 to 58.4 μg L−1. The analysis shows extensive spatial and temporal presence of phthalates resulting from dispersed phthalate sources throughout the karst aquifers. Hydrogeological factors are significantly more important in predicting the presence and concentrations of phthalates in eogenetic karst aquifers than anthropogenic factors. Among the hydrogeological factors, time of detection and hydraulic conductivities larger than 300 m d−1 are the most influential factors. Persistent presence through time reflects continuous sources of phthalates entering the aquifers and a high capacity of the karst aquifers to store and slowly release contaminants for long periods of time. The influence of hydraulic conductivity reveals the importance of contaminant fate and transport mechanisms from contamination sources. This study improves the understanding of factors affecting the spatial variability and fate of phthalates in karst aquifers, and allows us to better predict their occurrence based on these factors.

The molecular marker-based chemical mass balance (MM-CMB) method performs well in the source apportionment of organic carbon (OC) but has some difficulty with contributions from primary sources to inorganic secondary ions when apportioning PM2.5 (particles with aerodynamic diameter of 2.5 μm or less) sources. Positive matrix factorization (PMF) with the input of inorganic and organic tracers can properly estimate the contributions of primary and secondary sources to inorganic secondary ions; however, PMF is unable to apportion several PM2.5 sources with large fractions of organic carbon and few elemental compositions. In this study regarding data collected in 2011 and 2012 at three sites in Wuhan, China, the MM-CMB model was used to apportion OC in the PM2.5, and the PMF model was used to apportion the inorganic ions (sulfate, nitrate, and ammonia), dust, and EC. The source contributions of PM2.5 were estimated by reconstructing masses of bulk chemical components that had been apportioned to real-world sources using suitable source apportionment methods. Good performance of this hybrid source apportionment strategy was observed with ten resolved factors, explaining 70–80% of measured PM2.5 mass on average. The hybrid strategy takes the advantages of both models in PM2.5 source apportionment and yields unique source apportionment results for PM2.5 bulk chemical components, which could provide new information for optimizing air quality regulations for the emission abatement of target PM mass and compositions for countries around the world.

Particulate matter (PM) is one of the most serious environmental problems, exacerbating respiratory and vascular illnesses. Plants have the ability to reduce non-point source PM pollution through retention on leaves and branches. Studies of the dynamic processes of PM retention by plants and the mechanisms influencing this process will help to improve the efficiency of urban greening for PM reduction. We examined dynamic processes of PM retention and the major factors influencing PM retention by six trees with different branch structure characteristics in wind tunnel experiments at three different wind speeds. The results showed that the changes of PM numbers retained by plant leaves over time were complex dynamic processes for which maximum values could exceed minimum values by over 10 times. The average value of PM measured in multiple periods and situations can be considered a reliable indicator of the ability of the plant to retain PM. The dynamic processes were similar for PM₁₀ and PM₂.₅. They could be clustered into three groups simulated by continually-rising, inverse U-shaped, and U-shaped polynomial functions, respectively. The processes were the synthetic effect of characteristics such as species, wind speed, period of exposure and their interactions. Continually-rising functions always explained PM retention in species with extremely complex branch structure. Inverse U-shaped processes explained PM retention in species with relatively simple branch structure and gentle wind. The U-shaped processes mainly explained PM retention at high wind speeds and in species with a relatively simple crown. These results indicate that using plants with complex crowns in urban greening and decreasing wind speed in plant communities increases the chance of continually-rising or inverse U-shaped relationships, which have a positive effect in reducing PM pollution.

There are substantial concerns that increasing levels of anthropogenic noise in the oceans may impact aquatic animals. Noise can affect animals physically, physiologically and behaviourally, but one of the most obvious effects is interference with acoustic communication. Acoustic communication often plays a crucial role in reproductive interactions and over 800 species of fish have been found to communicate acoustically. There is very little data on whether noise affects reproduction in aquatic animals, and none in relation to acoustic communication. In this study we tested the effect of continuous noise on courtship behaviour in two closely-related marine fishes: the two-spotted goby (Gobiusculus flavescens) and the painted goby (Pomatoschistus pictus) in aquarium experiments. Both species use visual and acoustic signals during courtship. In the two-spotted goby we used a repeated-measures design testing the same individuals in the noise and the control treatment, in alternating order. For the painted goby we allowed females to spawn, precluding a repeated-measures design, but permitting a test of the effect of noise on female spawning decisions. Males of both species reduced acoustic courtship, but only painted gobies also showed less visual courtship in the noise treatment compared to the control. Female painted gobies were less likely to spawn in the noise treatment. Thus, our results provide experimental evidence for negative effects of noise on acoustic communication and spawning success. Spawning is a crucial component of reproduction. Therefore, even though laboratory results should not be extrapolated directly to field populations, our results suggest that reproductive success may be sensitive to noise pollution, potentially reducing fitness.

The water level fluctuation zone (WLFZ) of the Three Gorges Reservoir (TGR) in China is a unique geomorphological unit that undergoes annual flooding and drying alternation cycle. The alternating redox conditions within the WLFZ are expected to result in dynamic cycling of reduced sulfur species, which could affect mercury (Hg) methylation due to the high affinity of reduced sulfur species to both inorganic divalent mercury (Hg(II)i) and methylmercury (MeHg). Variations of inorganic sulfur species (measured as acid volatile sulfide, chromium reductive sulfur, elemental sulfur, and water-soluble sulfate), total mercury (THg) and MeHg were studied at two typical WLFZ sites in the TGR from July 2015 to June 2016. Whereas the water-soluble sulfate contents stayed essentially constant, the reduced inorganic sulfur contents varied greatly as the water level changed. Compared with the control soils, the MeHg contents in the WLFZ soils increased, suggesting that water level fluctuations accelerated the methylation process of Hg(II)i. In situ Hg(II)i-methylation also appeared to occur in the sub-layer of the drained sediment during the draw-down season. The significant correlation between MeHg and elemental sulfur (S(0)) further suggests that polysulfides may have played a role in Hg(II)i-methylation by increasing the bioavailable Hg(II)i content in the WLFZ of the TGR.

E-waste generation has become a serious environmental challenge worldwide. The global quantity of e-waste was estimated 44.7 million metric tons (Mt) in 2016. The improper recycling of e-waste is still a challenging issue in developing countries.The objectives of this a review article to present comprehensive information of recent studied on environment pollution and effect on human health in China.The search engines consulted, period of publications reviewed 2015–2018. For search study, we used different key words: ‘improper recycling’, ‘primitive recycling,’ ‘backyard recycling,’ ‘e-waste,’ ‘WEEE’, and the studies related to improper recycling of e-waste.According to reports, the e-waste recycled by unorganized sectors in China. These unorganized sector workers daily go for work, such as e-waste collection from consumer house and manual dismantling of e-waste by using simple method, at unauthorized workshop. These backyard workshop are reported in small clusters in or around city e.g., Qingyuan village; Taizhou, Longtang Town, Guiyu, nearby Nanyang River and Beigang River in China.The earlier reported studies directed the heavy metals effect (causing effects both acute and chronic effects; respiratory irritation, reproductive problem, cardiovascular and urinary infection/disease) on human health. According the reports, the improper recycling of e-waste which need to be address for the environment protection and prevention of public health risk. However, if e-waste exposure is not avoided very well, the associated contamination will be continuing, and simultaneously needful to increase the awareness for proper e-waste management in China.In order to solve the e-waste problem in China, more detail research is needed. Furthermore, for environment protection and health safety, the proper e-waste dismantling techniques, environmentally sound management, and the regular monitoring are very important.

Contamination of aquatic habitats with pharmaceuticals is a major environmental concern. Recent studies have detected pharmaceutical pollutants in a wide array of ecosystems and organisms, with many of these contaminants being highly resistant to biodegradation and capable of eliciting sub-lethal effects in non-target species. One such pollutant is fluoxetine, a widely prescribed antidepressant, which is frequently detected in surface waters globally and can alter physiology and behaviour in aquatic organisms. Despite this, relatively little is known about the potential for fluoxetine to disrupt mechanisms of sexual selection. Here, we investigate the impacts of 30-day exposure to two environmentally realistic levels of fluoxetine (low and high) on mechanisms of pre- and post-copulatory sexual selection in the eastern mosquitofish (Gambusia holbrooki). We tested 1) male mating behaviour in the absence or presence of a competitor male, and 2) sperm quality and quantity. We found that high-fluoxetine exposure increased male copulatory behaviour in the absence of a competitor, while no effect was detected under male-male competition. Further, fluoxetine exposure at both concentrations increased total sperm count relative to males from the control group, while no significant change in sperm quality was observed. Lastly, low-fluoxetine males showed a significant reduction in condition index (mass relative to length). Our study is the first to show altered mechanisms of both pre- and post-copulatory sexual selection in an aquatic species resulting from environmentally realistic fluoxetine exposure, highlighting the capacity of pharmaceutical pollution to interfere with sensitive reproductive processes in wildlife.

We investigated the ability of the aquatic fern Azolla to take up ciprofloxacin (Cipro), as well as the effects of that antibiotic on the N-fixing process in plants grown in medium deprived (-N) or provided (+N) with nitrogen (N). Azolla was seen to accumulate Cipro at concentrations greater than 160 μg g⁻¹ dry weight when cultivated in 3.05 mg Cipro l⁻¹, indicating it as a candidate for Cipro recovery from water. Although Cipro was not seen to interfere with the heterocyst/vegetative cell ratios, the antibiotic promoted changes with carbon and nitrogen metabolism in plants. Decreased photosynthesis and nitrogenase activity, and altered plant's amino acid profile, with decreases in cell N concentrations, were observed. The removal of N from the growth medium accentuated the deleterious effects of Cipro, resulting in lower photosynthesis, N-fixation, and assimilation rates, and increased hydrogen peroxide accumulation. Our results shown that Cipro may constrain the use of Azolla as a biofertilizer species due to its interference with nitrogen fixation processes.

Given that cadmium (Cd) uptake by plants is linked to transpiration rate and activity of antioxidant enzymes and further that silicon (Si) can regulate them, it was hypothesized that improved Si nutrition could reduce Cd concentration in plants. Thus, present study was carried out to elucidate the positive effect of Si nutrition on the growth, activities of antioxidant enzymes and tissue cadmium (Cd) concentration in Cd-tolerant (Iqbal-2000) and Cd-sensitive wheat (Triticum aestivum L.) cultivars. Fifteen days after seedling transplantation, 15 μM Cd stress alone and in combination with 0.6 mM Si was applied. Silicon application improved root and shoot dry matter of Cd-sensitive cultivar Sehar-2006 while the effect was non-significant in Cd-tolerant cultivar Iqbal-2000. Silicon-treated Cd-sensitive cultivar showed marked improvements in chlorophyll content and photosynthesis, while stomatal conductance and transpiration rate decreased by Si application. Silicon treatment enhanced the activities of enzymatic antioxidants including catalase, ascorbate peroxidase, guaiacol peroxidase and superoxide dismutase and the increase was higher for Cd-tolerant cultivar Iqbal-2000. Although Si nutrition depressed malondialdehyde (MDA) content in both Cd-stressed cultivars, the response was more evident in Cd-sensitive Sehar-2006. Lower lipid peroxidation was related to Si-induced increase in antioxidant activities only in Cd-sensitive cultivar. Silicon application decreased Cd accumulation in the roots and shoots of both the cultivars. The decrease in shoot Cd was associated with a decrease in Cd uptake by roots and Cd translocation from roots to shoots. Overall, it is concluded that Si suppressed Cd contents by decreasing transpiration rate in Cd-sensitive cultivar and by increasing antioxidant activity in Cd-tolerant cultivar.

Sugars and n-alkanes are important organic constituents of atmospheric fine particulate matter (PM₂.₅). For better understanding their sources and seasonal variations in urban atmosphere, sugar compounds (anhydrosugars, sugars and sugar alcohols) and homologue n-alkanes (C₁₈–C₃₇) were studied in PM₂.₅ samples collected from September 2013 to July 2014 in Beijing, China. In general, all measured compounds showed the lowest levels in summer. Higher concentrations of sugar compounds and n-alkanes were observed in winter, probably due to elevated combustion emissions (e.g., coal, biofuel and agricultural residue burning) and stable meteorological conditions during heating season. Levoglucosan was the major sugar species in all seasons particularly in autumn and winter, highlighting the significant contribution of biomass burning to fine organic aerosols throughout the whole year especially in cold seasons. Plant waxes contributed to n-alkanes the most in late spring (54.5%) and the least in winter (11.6%); while fossil fuel combustion had the largest contribution in winter (385 ng m⁻³). The weak odd-carbon predominance of n-alkanes in wintertime aerosols also suggests fossil fuel combustion as the important source of organic aerosols in the heating season. Soil resuspension, fossil fuel combustion and biomass burning, and secondary sources are the main sources of OC in PM₂.₅ at Beijing. The seasonal variation in source contributions indicates that meteorological condition is a key factor in controlling PM₂.₅ levels. Furthermore, dust storms in spring can strongly enhance the atmospheric level of fine organic matter in Beijing.