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Factory employment exposure and human health: Evidence from rural China
2020
Xu, Xiangbo | Sun, Mingxing | Zhang, Linxiu | Fu, Chao | Bai, Yunli | Li, Chang
Quantitating the health effects of employment history in factories, especially polluting ones, is essential for understanding the benefits or losses of industrialization in rural areas. Using a traced subset of nationwide panel data from 2005 covering five provinces, 101 villages, and 2026 households (collected recently in 2016) and the econometric models, this study estimated the effect of factory employment history on workers' health. The results showed that: the absolute number of factory workers increased from 1998 to 2015, and the proportion of factory workers was 7.68% in 2015; the absolute number and the proportion of farmers decreased from 63.84% in 1998 to 29.06% in 2015. Given that all the respondents live in rural areas, the HlthPlace (the first place the individual went to for their last illness in 2015) was selected as the main dependent variable of interest, and Hlthexp (Healthcare expenditure per person at last illness in 2015) and self-reported health were used as auxiliary dependent variables. The findings revealed that, after controlling the characteristics of individual, household, hospital and area, a one year increase of factory employment history corresponded to a 0.035 level increase in the probability of people choosing high-level hospital (p < 0.01) and a 237.61 yuan increase in healthcare expenditure (p < 0.1). The results also showed the adverse effect of self-reported health on factory employment history (p < 0.01). In addition, the relationship between the farming history and health was evaluated, and the econometric results showed that compared with factory employment history, farming history had opposite impacts on health (p < 0.01). Finally, the robustness check showed that the empirical results were reliable and that the initial results were robust. Generally, this study revealed the effect of overall factory employment on health, which is a useful research supplement to the studies on the health effects of specific pollution exposure.
Mostrar más [+] Menos [-]Effects of microplastics and mercury on manila clam Ruditapes philippinarum: Feeding rate, immunomodulation, histopathology and oxidative stress
2020
Sıkdokur, Ercan | Belivermiş, Murat | Sezer, Narin | Pekmez, Murat | Bulan, Ömür Karabulut | Kılıç, Önder
Plastic pollution, which is one of the most important environmental problems at the present time, has been understood recently, and the effects of this pollution on ecosystem and biota are becoming a growing problem, especially in the aquatic ecosystems. Direct or indirect exposure to those particles leads to adverse effects on marine organisms. In the marine environment, plastic materials interact with other pollutants such as metals, thereby affecting the uptake levels of those pollutants in marine organisms. In the present study, the Manila clam Ruditapes philippinarum was exposed to polyethylene microbeads and mercury chloride in single, combined and incubated form at environmentally relative concentrations for one week in controlled laboratory conditions. The uptake and tissue distribution of both stressors as well as the vector role of microplastics on mercury uptake in the organisms were investigated. Filtration rates, biomarkers for immunomodulation and oxidative stress, and histological alterations were also evaluated. Microplastics were ingested by the clams, and translocated to the various tissues. However, contaminated microplastics displayed a negligible vector role in terms of mercury bioaccumulation in the clams. The single and interactive exposure of the stressors reduced the filtration rate in the clams. Both pollutants affected the immune system of the organisms. Histological alterations were determined in the gill and digestive gland tissues of the clams among the treatment groups, although oxidative stress biomarkers remained unchanged. This study suggests that the vector role of polyethylene microplastics in mercury uptake is negligible and reveals that the single and interactive one-week exposure of two pollutants induce toxicity in the manila clams.
Mostrar más [+] Menos [-]Increased temperature and lower resource quality exacerbate chloride toxicity to larval Lithobates sylvaticus (wood frog)
2020
Green, Frank B. | Salice, Christopher J.
A chemical contaminant of growing concern to freshwater aquatic organisms, including many amphibians, is chloride ion. The salinization of freshwater ecosystems is likely caused, in part, by the application of massive amounts of road de-icing salts to roadways during winter months. The issue of freshwater salinization has become the subject of many toxicity studies and is often investigated in conjunction with other chemical stressors. However, few published studies attempt to investigate the interactions of elevated chloride concentration and increased temperature. Further, no studies have investigated the gap between the recommended feeding conditions typically used in standard toxicity tests and those that may exist in natural amphibian habitats. This study addressed the critical issues of elevated chloride, increased temperature, and variation in food quality. We conducted a 96-h acute toxicity test to investigate acute chloride toxicity as impacted by different diets, as well as a chronic toxicity test to investigate the impacts of chloride, temperature, and resource quality on the survival and development of larval Lithobates sylvaticus (wood frogs). Chloride LC₅₀s ± 1 SE were 3769.22 ± 589.05, 2133.00 ± 185.95, and 2644.69 ± 209.73 mg Cl⁻/L were for non-fed, low-protein diet, and high-protein diet, respectively. For the chronic toxicity study, elevated chloride decreased tadpole survival. Increased temperature, and lower resource quality, were found negatively impacted survival of tadpoles and altered time-to-metamorphosis. This study shows that environmentally relevant concentrations of chloride, temperatures, and the protein content of the diet all exert critical effects on larval wood frogs.
Mostrar más [+] Menos [-]Evaporation rates and pollutants emission from heated cooking oils and influencing factors
2020
Adeniran, Jamiu Adetayo | Yusuf, Rafiu Olasunkanmi | Abdulkadir, Mariam Oyinkansola | Yusuf, Muhammad-Najeeb O. | Abdulraheem, Khadija Abdulkareem | Adeoye, Babatunde Kazeem | Sonibare, Jacob Ademola | Du, Mingxi
The heating of edible oils during cooking activities promotes the emissions of pollutants that have adverse impacts on the health of humans. This study investigated the evaporative emissions of fifteen (15) commonly used cooking oils. Split-plot experimental design under the response surface methodology framework was used to study singular and interaction effects of influencing parameters (temperature, volume of cooking oil and time) on cooking oil evaporation rate and pollutants emissions (i.e. Particulate matter of aerodynamic diameter ≤1 μm (PM₁.₀); ≤2.5 μm (PM₂.₅); ≤10 μm (PM₁₀); Total Suspended Particulate (TSP); Total Volatile Organic Compounds -TVOCs, and Carbon Monoxide- CO) on a groundnut oil sample that served as a case study. Obtained values of density, viscosity, kinematic viscosity, smoke, flash and fire points were; 873–917 kg/m³; 1.12–9.7 kg/ms; 2.4–3.4 m²/s; 96 -100 °C; 124–179 °C and 142–186 °C, respectively. The role of temperature as the most significant parameter influencing the rate of evaporative emissions was established. Evaporation rate and pollutants emission from unrefined samples were the highest. The restricted maximum likelihood (REML) analysis results suggested a strong relationship between the actual values and the predicted values as R-squared values obtained were greater than 0.8 for all the responses. These results suggest that minimal rates of evaporation and pollutants emission from heating cooking oils can be achieved with a high volume of the cooking oil at moderate temperature levels.
Mostrar más [+] Menos [-]Triclocarban affects earthworms during long-term exposure: Behavior, cytotoxicity, oxidative stress and genotoxicity assessments
2020
Sales Junior, Sidney Fernandes | Vallerie, Quentin | de Farias Araujo, Gabriel | Soares, Lorena Oliveira Souza | Oliveira da Silva, Evelyn | Correia, Fábio Veríssimo | Saggioro, Enrico Mendes
Triclocarban (TCC) is a contaminant of emerging concern widely applied as an antimicrobial in personal care products and introduced into the terrestrial environment through the application of biosolids (i.e., treated sewage sludge) in agriculture. Displaying the potential to bioaccumulate in the food chain and a high half-life in the soil, the presence of this compound in the environment may lead to potential ecological risks. In this context, TCC toxicity assessments in Eisenia andrei earthworms were carried out through acute, avoidance and chronic tests following cytotoxicity, antioxidant system, i.e. acatalase (CAT), glutathione-S-transferase (GST), glutathione (GSH), lipid peroxidation (LPO), and DNA damage (comet assay) evaluations. An LC₅₀ of 3.3 ± 1.6 mg cm⁻² in the acute contact test and an EC₅₀ of 1.92 ± 0.31 mg kg⁻¹ in the avoidance test during 72 h and 48 h, respectively, were obtained. The behavioral test indicates earthworm avoidance from 15.0 mg kg⁻¹ of TCC. During chronic soil exposure, a 44% reduction in earthworm cell viability was observed after 14 days of exposure to 10 mg kg⁻¹ TCC, while an increase in the percentage of amoebocyte cells also ocurred. Chronic exposure to TCC led to reduced CAT and GST activities, decreased GSH levels and increased LPO in exposed organisms. DNA damage was observed after 45 days from a 1 mg kg⁻¹ dose of TCC. Therefore, TCC exhibits toxicological potential to Eisenia andrei earthworms, mainly during long-term exposures. This study provides mechanistic earthworm information towards understanding the environmental and human health implications of TCC exposure and draws attention to correct biosolid management.
Mostrar más [+] Menos [-]Particulate emissions of a modern diesel passenger car under laboratory and real-world transient driving conditions
2020
Wihersaari, Hugo | Pirjola, Liisa | Karjalainen, Panu | Saukko, Erkka | Kuuluvainen, Heino | Kulmala, Kari | Keskinen, Jorma | Rönkkö, Topi
Exhaust emissions from diesel vehicles are significant sources of air pollution. In this study, particle number emissions and size distributions of a modern Euro 5b -compliant diesel passenger car exhaust were measured under the NEDC and US06 standard cycles as well as during different transient driving cycles. The measurements were conducted on a chassis dynamometer; in addition, the transient cycles were repeated on-road by a chase method. Since the diesel particulate filter (DPF) removed practically all particles from the engine exhaust, it was by-passed during most of the measurements in order to determine effects of lubricant on the engine-out exhaust aerosol. Driving conditions and lubricant properties strongly affected exhaust emissions, especially the number emissions and volatility properties of particles. During acceleration and steady speeds particle emissions consisted of non-volatile soot particles mainly larger than ∼50 nm independently of the lubricant used. Instead, during engine motoring particle number size distribution was bimodal with the modes peaking at 10–20 nm and 100 nm. Thermal treatment indicated that the larger mode consisted of non-volatile particles, whereas the nanoparticles had a non-volatile core with volatile material condensed on the surfaces; approximately, 59–64% of the emitted nanoparticles evaporated. Since during engine braking the engine was not fueled, the origin of these particles is lubricant oil. The particle number emission factors over the different cycles varied from 1.0 × 10¹⁴ to 1.3 × 10¹⁵ #/km, and engine motoring related particle emissions contributed 12–65% of the total particle emissions. The results from the laboratory and on-road transient tests agreed well. According to authors’ knowledge, high particle formation during engine braking under real-world driving conditions has not been reported from diesel passenger cars.
Mostrar más [+] Menos [-]Emission characteristics and health risk assessment of VOCs from a food waste anaerobic digestion plant: A case study of Suzhou, China
2020
Zheng, Guodi | Liu, Junwan | Shao, Zhuze | Chen, Tongbin
The process of anaerobic digestion in food waste treatment plants generates a large amount of volatile organic compounds (VOCs). Long-term exposure to this exhaust gas can pose a threat to the health of workers and people living nearby. In this study, VOCs emitted from different working units in a food waste anaerobic digestion plant were monitored for a year. Variations in VOCs emitted from each unit were analyzed and a health risk assessment was conducted for each working unit. The results show that the concentration of VOCs in different units varied greatly. The highest cumulative concentration of VOCs appeared in the hydrothermal hydrolysis unit (3.49 × 10⁴ μg/m³), followed by the sorting/crushing room (8.97 × 10³ μg/m³), anaerobic digestion unit (6.21 × 10² μg/m³), and biogas production unit (2.01 × 10² μg/m³). Oxygenated compounds and terpenes were the major components of the emitted VOCs, accounting for more than 98% of total VOC emissions. The carcinogenic risk in the plant exceeded the safety threshold (ILCR<1 × 10⁻⁶), while the non-carcinogenic risk was within the acceptable range (HI < 1). The carcinogenic risk from the hydrothermal hydrolysis unit was the highest, reaching 4.4 × 10⁻⁵, and was labeled as “probable risk.” The carcinogenic risk at the plant boundary was 1.2 × 10⁻⁵, indicating exhaust gases can cause a health threat to neighbors. Therefore, management VOCs in anaerobic digestion plants should receive more attention, and employees should minimize the time they spend in the hydrothermal hydrolysis unit.
Mostrar más [+] Menos [-]Chronic nitrogen addition promotes dissolved organic carbon accumulation in a temperate freshwater wetland
2020
Mao, Rong | Zhang, Xin-Hou | Song, Chang-Chun
Temperate wetlands have been undergoing increased nitrogen (N) inputs in the past decades, yet its influence on dissolved organic carbon (DOC) dynamics is still elusive in these ecosystems. Here, using a field multi-level N addition (0, 6, 12, and 24 g N m⁻² year⁻¹) experiment, we investigated the changes in aboveground plant biomass, DOC production from plant litters, DOC biodegradation, and DOC concentration in surface water and soil pore water (0–15 cm depth) following 10 years of N addition in a freshwater marsh of Northeast China. We observed that, irrespective of N addition levels, N addition caused an increase in DOC production from plant litters under both non-flooded and flooded conditions. Conversely, DOC biodegradation was inhibited by N addition in both surface water and soil pore water. Because of enhanced DOC production from plant litters and declined DOC biodegradation, N addition elevated DOC concentration in surface water and soil pore water across the growing season. In addition, long-term N addition increased aboveground plant biomass, but decreased species richness. Our results suggest that long-term N enrichment promotes DOC accumulation through the contrasting effects on litter-derived DOC production and microbial decomposition of DOC in temperate wetlands.
Mostrar más [+] Menos [-]Per- and polyfluoroalkyl substances (PFASs) in blood of captive Siberian tigers in China: Occurrence and associations with biochemical parameters
2020
Wang, Yajun | Yao, Jingzhi | Dai, Jiayin | Ma, Liying | Liu, Dan | Xu, Haitao | Cui, Qianqian | Ma, Jianzhang | Zhang, Hongxia
Per- and polyfluoroalkyl substances (PFASs) have been ubiquitously detected in the environment and marine animals. However, little is known about these substances and their associations with health parameters in wild terrestrial mammals. In this study, we determined PFAS levels and distribution in the blood of captive Siberian tigers in Harbin, China, and evaluated potential exposure pathways by daily intake. In addition, for the first time, we explored the associations between serum PFAS concentrations and clinical parameters. Results showed that perfluorooctanoate (PFOA) was the dominant PFAS compound in blood (accounting for 64%), followed by perfluorooctanesulfonate (PFOS). In addition, 6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFESA) concentrations were also detected in blood and dietary food. Furthermore, significant positive age relationships were observed for levels of perfluoroheptanoate (PFHpA), PFOA, PFOS, and 6:2 Cl-PFESA in the blood of female tigers. Results showed that PFOA and PFOS in dietary food accounted for over 70% of total daily intake of PFASs, indicating that meat consumption is a predominant exposure pathway in tigers. We also found positive associations between higher exposure to PFASs (including PFOA, PFOS, and 6:2 Cl-PFESA) and elevated serum levels of alanine transaminase (ALT), a marker of liver damage. Thus, comprehensive health assessments of PFAS burdens in wildlife are needed.
Mostrar más [+] Menos [-]Spatio-temporal patterns of air pollution in China from 2015 to 2018 and implications for health risks
2020
Kuerban, Mireadili | Waili, Yizaitiguli | Fan, Fan | Liu, Ye | Qin, Wei | Dore, Anthony J. | Peng, Jingjing | Xu, Wen | Zhang, Fusuo
China has been seriously affected by particulate matter (PM) and gaseous pollutants in the atmosphere. In this study, we systematically analyse the spatio-temporal patterns of PM₂.₅, PM₁₀, SO₂, CO, NO₂, and O₃ and the associated health risks, using data collected from 1498 national air quality monitoring sites. An analysis of the averaged data from all the sites indicated that, from 2015 to 2018, annual mean concentrations of PM₂.₅, PM₁₀, SO₂ and CO declined by 3.2 μg m⁻³, 3.7 μg m⁻³, 3.9 μg m⁻³, and 0.1 mg m⁻³, respectively. In contrast, those of NO₂ and O₃ increased at rates of 0.4 and 3.1 μg m⁻³, respectively. Except for O₃, the annual mean concentrations of all pollutants were generally the highest in North China and lowest in the Tibetan Plateau. The concentrations were generally higher in the north of the country than in the south. In all regions of China, the pollutant concentrations were the highest in winter and lowest in summer, except for O₃, which showed an opposite seasonal pattern. Overall, the seasonal mean concentrations of all the pollutants (except for O₃) significantly decreased between the same seasons in 2018 and 2015, whereas the seasonal mean O₃ concentrations generally significantly increased, and/or remained at stable levels in all four seasons except for winter. Diurnal variations of all pollutants (except for O₃) exhibited a bimodal pattern with peaks between 8:00 and 11:00 a.m. and 9:00 and 12:00 p.m., whereas O₃ exhibited a unimodal pattern with maximum values between 5:00 and 7:00 p.m. No significant differences in the daily mean concentrations of all pollutants were found between weekdays and weekends in all regions, except for PM₂.₅ and PM₁₀ in Northeast China. In Northwest China and Southeast China, PM₂.₅ showed stronger correlations with NO₂ relative to SO₂, suggesting that NOₓ emission control may be more effective than SO₂ emission control for alleviating PM₂.₅ formation. Compared with 2015, the total PM₂.₅-attributable mortality, number of respiratory and cardiovascular diseases, and incidence of chronic bronchitis decreased overall by 23.4%–26.9% in 2018. In contrast, for O₃-attributable deaths, there was an increase of 18.9%. Our study not only improves the understanding of the spatial and temporal patterns of air pollutants in China, but also highlights that synchronous control of PM₂.₅ and O₃ pollution should be implemented to achieve dual benefits in protecting human health.
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