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Inflammatory and oxidative stress responses of healthy adults to changes in personal air pollutant exposure Full text
2020
Hu, Xinyan | He, Linchen | Zhang, Junfeng | Qiu, Xinghua | Zhang, Yinping | Mo, Jinhan | Day, Drew B. | Xiang, Jianbang | Gong, Jicheng
Exposure to air pollutants has been associated with respiratory and cardiovascular mortality, but the underlying molecular mechanisms remain inadequately understood. We aimed to examine molecular-level inflammatory and oxidative stress responses to personal air pollutant exposure. Fifty-three healthy adults aged 22–52 were measured three times for their blood inflammatory cytokines and urinary malondialdehyde (MDA, an oxidative stress biomarker) within 2 consecutive months. Pollutant concentrations monitored indoors and outdoors were combined with the time-activity data to calculate personal O₃, PM₂.₅, NO₂, and SO₂ exposures averaged over 12 h, 24 h, 1 week, and 2 weeks, respectively, prior to biospecimen collection. Inflammatory cytokines and MDA were associated with pollutant exposures using linear mixed-effects models controlling for various covariates. After adjusting for a co-pollutant, we found that concentrations of proinflammatory cytokines were significantly and negatively associated with 12-h O₃ exposures and significantly but positively associated with 2-week O₃ exposures. We also found significant and positive associations of proinflammatory cytokines with 12-h and 24-h NO₂ exposures, respectively. However, we did not find clear associations of PM₂.₅ and SO₂ exposure with proinflammatory cytokines and with MDA. The removal of an O₃-generating electrostatic precipitator in the mechanical ventilation systems of the offices and residences of the subjects was associated with significant decreases in IL-1β, IL-2, IL-6, IL-8, IL-17A, and TNF-α. These findings suggest that exposure to O₃ for different time durations may affect systemic inflammatory responses in different ways.
Show more [+] Less [-]Associations between renal functions and exposure of arsenic and polycyclic aromatic hydrocarbon in adults living near a petrochemical complex Full text
2020
Yuan, Tzu-Hsuen | Ke, Deng-Yuan | Wang, Joyce En-Hua | Chan, Chang-Chuan
The understanding for the impact of petrochemical pollutants exposure on renal functions is limited.Our study examined the associations between renal functions and pollutants exposure in adult residents living in the vicinity of a petrochemical industry.We recruited 2069 adult residents near a big petrochemical complex in Taiwan in 2009–2012, and they were categorized into high exposure (HE) and low exposure (LE) groups based on their address to source by 10 km radius. Study subjects were measured the urinary levels of arsenic, cadmium, mercury, thallium, and 1-hydroxypyrene (1-OHP). The estimated glomerular filtration rate (eGFR) was calculated using the Taiwanese Chronic Kidney Disease Epidemiology Collaboration equation, and the chronic kidney disease (CKD) prevalence and risks were defined according to KDIGO 2012 guidelines. Adjusted generalized linear and logistic regression models were applied to evaluate the associations between petrochemical exposure and renal functions.Subjects in the HE areas had significantly lower eGFR, higher CKD prevalence, and higher levels of urinary arsenic, cadmium, mercury, thallium and 1-OHP. The closer to complex and high exposure group of study subjects were significantly associated with the decrease in eGFR, higher ORs for CKD and high-intermediate risk of CKD. In addition, the study subjects who had two-fold urinary arsenic and 1-OHP levels were significantly with decreased 0.68 and 0.49 ml/min/1.73 m2 of eGFR, respectively.Residing closer and higher arsenic and polycyclic aromatic hydrocarbon exposure were associated with the renal impairment and risks of CKD among the residential population near the petrochemical industry.
Show more [+] Less [-]Exposure assessment of emissions from mobile food carts on New York City streets Full text
2020
Nahar, Kamrun | Rahman, Md Mostafijur | Raja, Amna | Thurston, George D. | Gordon, Terry
Food carts are common along streets in cities throughout the world. In North America, food cart vendors generally use propane, charcoal, or both propane and charcoal (P and C) for food preparation. Although cooking emissions are known to be a major source of indoor air pollution, there is limited knowledge on outdoor cooking’s impact on the ambient environment and, in particular, the relative contribution of the different cooking fuels. This field study investigated the air pollution the public is exposed to in the micro-environment around 19 food carts classified into 3 groups: propane, charcoal, and P and C carts. Concentrations near the food carts were measured using both real-time and filter-based methods. Mean real-time concentrations of PM₂.₅, BC₂.₅, and particle counts were highest near the charcoal food carts: 196 μg/m³, 5.49 μg/m³, and 69,000 particles/cm³, respectively, with peak exposures of 1520 μg/m³, 67.9 μg/m³, and 235,000 particles/cm³, respectively. In order of pollution emission impacts: charcoal > P and C > propane carts. Thus, significant differences in air pollution emissions occurred in the vicinity of mobile food carts, depending on the fuel used in food preparation. Local air pollution polices should consider these emission factors in regulating food cart vendor operations.
Show more [+] Less [-]Association between phthalate exposure and risk of spontaneous pregnancy loss: A systematic review and meta-analysis Full text
2020
Zhang, Hong | Gao, Fumei | Ben, Yujie | Su, Yuping
Numerous studies suggested that phthalates might be associated with increased risk of spontaneous pregnancy loss. However, these results were conflicting and inconclusive. Thus we performed this systematic review and meta-analysis to assess the relationship between phthalate exposure and risk of pregnancy loss. We searched PubMed, EMBASE, Web of Science and major Chinese literature databases for studies investigating phthalates and spontaneous pregnancy loss. Pooled odds ratio (OR) with 95% confident interval (CI) were calculated for risk estimate. A total of 8 studies involving 4713 participants (including 651 cases and 4062 controls) were enrolled in the present meta-analysis. Our pooled results showed that spontaneous pregnancy loss was associated with higher urinary levels of monobutyl phthalate (MBP) (OR: 1.34, 95% CI: 1.04–1.72), mono(2-ethylhexyl) phthalate (MEHP) (OR: 1.57, 95% CI: 1.29–1.90), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) (OR: 1.59, 95% CI: 1.23–2.07) and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) (OR: 1.47, 95% CI: 1.15–1.89). Indirect estimate of di-2-ethylhexyl phthalate (DEHP) levels, which were pooled from molar sum of urinary DEHP metabolites and hair DEHP, were also correlated with elevated risk of spontaneous pregnancy loss (OR: 1.79, 95% CI: 1.27–2.53). No significant association was found regarding urinary concentrations of monomethyl phthalate (MMP), monoethyl phthalate (MEP), mono-isobutyl phthalate (MiBP), monobenzyl phthalate (MBzP) or mono(2-ethyl-5-carboxypentyl) phthalate (MECPP). Our findings indicate that phthalate exposure might be a risk factor for spontaneous pregnancy loss. Given indirect estimate of phthalate exposure by evaluating its metabolite levels, our results should be interpreted with caution.
Show more [+] Less [-]The association between urine di-(2-ethylhexyl) phthalate metabolites, global DNA methylation, and subclinical atherosclerosis in a young Taiwanese population Full text
2020
Lin, Chien-Yu | Lee, Hui-Ling | Hwang, Yi-Ting | Wang, Chikang | Hsieh, Chia-Jung | Wu, Charlene | Sung, Fung-Chang | Su, Ta-Chen
Di-(2-ethylhexyl) phthalate (DEHP) has been utilized in many products for years. DEHP exposure has been linked to cardiovascular diseases (CVD) and its risk factors. Recent evidence has found a crucial role for epigenetics, including DNA methylation, in CVD. Moreover, DEHP exposure has proved to alter DNA methylation in epidemiological studies. However, the interplay between DEHP exposure, global DNA methylation, and atherosclerosis has never been reported. In this current study, we enrolled 793 participants (12–30 years) from a Taiwanese population to investigate the association between concentrations of DEHP metabolites, 5mdC/dG (global DNA methylation marker) and the carotid intima-media thickness (CIMT). The results showed urine mono-2-ethylhexyl phthalate (MEHP) level was positively correlated with 5mdC/dG and CIMT, respectively. In logistic regression models, the odds ratios (OR) of thicker CIMT (greater than 75ᵗʰ percentile) with one unit increase in ln-MEHP level was higher when levels of 5mdC/dG were above 50%. In structural equation model, the result showed urine MEHP levels are directly associated with CIMT. Moreover, MEHP had an indirect association with CIMT through the 5mdC/dG after adjusting other confounding effects. In the current study, urine DEHP metabolite levels were positively correlated with 5mdC/dG, and CIMT. Our results showed DEHP had a direct and indirect association with CIMT through the 5mdC/dG. The finding implies that DNA methylation may mediate the association between DEHP exposures and subclinical atherosclerosis in this young population. Future effort is needed to elucidate the causal relationship between DEHP exposure, DNA methylation and CVD.
Show more [+] Less [-]The role of metal contamination in shaping microbial communities in heavily polluted marine sediments Full text
2020
Di Cesare, Andrea | Pjevac, Petra | Eckert, Ester | Curkov, Neven | Miko Šparica, Maritina | Corno, Gianluca | Orlić, Sandi
Microorganisms in coastal sediments are fundamental for ecosystem functioning, and regulate processes relevant in global biogeochemical cycles. Still, our understanding of the effects anthropogenic perturbation and pollution can have on microbial communities in marine sediments is limited. We surveyed the microbial diversity, and the occurrence and abundance of metal and antibiotic resistance genes is sediments collected from the Pula Bay (Croatia), one of the most significantly polluted sites along the Croatian coast. With a collection of 14 samples from the bay area, we were able to generate a detailed status quo picture of a site that only recently started a cleaning and remediation process (closing of sewage pipes and reduction of industrial activity). The concentrations of heavy metals in Pula Bay sediments are significantly higher than in pristine sediments from the Adriatic Sea, and in some cases, manifold exceed international sediment quality guidelines. While the sedimentary concentrations of heavy metals did significantly influence the abundance of the tested metal resistance genes, no strong effect of heavy metal pollution on the overall microbial community composition was observed. Like in many other marine sediments, Gammaproteobacteria, Bacteroidota and Desulfobacterota dominated the microbial community composition in most samples, and community assembly was primarily driven by water column depth and nutrient (carbon and nitrogen) availability, regardless of the degree of heavy metal pollution.
Show more [+] Less [-]Short-term associations between size-fractionated particulate air pollution and COPD mortality in Shanghai, China Full text
2020
Peng, Li | Xiao, Shaotan | Gao, Wei | Zhou, Yi | Zhou, Ji | Yang, Dandan | Ye, Xiaofang
Particulate air pollution is a continuing challenge in China, and its adverse effects on chronic obstructive pulmonary disease (COPD) have been widely reported. However, epidemiological evidence on the associations between size-fractionated particle number concentrations (PNCs) and COPD mortality is limited. In this study, we utilized a time-series approach to investigate the associations between PNCs of particles at 0.25–10 μm in diameter and COPD mortality in Shanghai, China. Quasi-Poisson regression generalized additive models were applied to evaluate these associations, with adjustment of time trend, day of week, holidays, temperature and relative humidity. Stratification analyses were performed by season and gender. There were a total of 3238 deaths due to COPD during the study period. We found that daily COPD deaths were significantly associated with PNCs of particles <0.5 μm, and the magnitude of associations increased with decreasing particle size. An interquartile range (IQR) increase in PNC₀.₂₅—₀.₂₈, PNC₀.₂₈—₀.₃, PNC₀.₃—₀.₃₅, PNC₀.₃₅—₀.₄, PNC₀.₄—₀.₄₅ and PNC₀.₄₅—₋₀.₅ was associated with increments of 7.51% (95%CI: 2.45%, 12.81%), 7.22% (95%CI: 2.16%, 12.53%), 6.95% (95%CI: 1.81%, 12.35%), 6.26% (95%CI: 1.25%, 11.52%), 5.24% (95%CI: 0.56%, 10.13%) and 4.15% (95%CI: 0.14%, 8.32%), respectively. The associations remained robustness after controlling for the mass concentrations of gaseous air pollutants. In stratification analyses, significant associations between PNCs and COPD mortality were observed in the cold seasons, and in males. Our results suggested that particles <0.5 μm in diameter might be most responsible for the adverse effects of particulate air pollution on COPD mortality, and COPD patients are more susceptible to PM air pollution in the cold seasons, especially for males.
Show more [+] Less [-]Influence of food (ciliate and phytoplankton) on the trophic transfer of inorganic and methyl-mercury in the Pacific cupped oyster Crassostrea gigas Full text
2020
Metian, Marc | Pouil, Simon | Dupuy, Christine | Teyssié, Jean-Louis | Warnau, Michel | Bustamante, Paco
Diet is an important route of mercury (Hg) uptake in marine organisms. Trophic transfer of Hg throughout the food webs may be influenced by various factors, including diet and Hg speciation. Bivalves such as oysters are widely used as bioindicators of trace element pollution such as Hg. Nevertheless, our current knowledge regarding their ability to accumulate Hg from their diet is mainly based on experiments performed using phytoplankton. In their natural environment, oysters feed on a variety of food items including ciliates, detritus, in addition to phytoplankton. The present study aimed at examining the influence of diet composition on the trophic transfer of inorganic Hg (iHg) and methylmercury (MeHg) in the Pacific cupped oyster Crassostrea gigas. The pulse-chase feeding method was used with two radiolabeled food items: a heterotrophic protist (Uronema marinum) and a phytoplanktonic diatom (Thalassiosira pseudonana). Depuration of dietary Hg in the oysters was followed for 50 d. Kinetic parameters including assimilation efficiency (AE) and efflux rate constant (kₑ) were calculated. Our results showed that oysters fed on ciliates assimilated 96 ± 1% and 31 ± 2% of the ingested MeHg and iHg, respectively whereas these elements were similarly assimilated in the oysters fed on phytoplankton (78 ± 3% and 86 ± 4% for MeHg and iHg, respectively). Mercury assimilation in oyster is thus diet dependent (significant differences in AE, p < 0.05), metal species-dependent and likely resulting from variations in Hg bioavailability in the two food items tested and a gut passage time-dependent of the ingested matrix.
Show more [+] Less [-]Internal dynamics of inorganic and methylmercury in a marine fish: Insights from mercury stable isotopes Full text
2020
Lee, Bong Joo | Kwon, Sae Yun | Yin, Runsheng | Li, Miling | Jung, Saebom | Lim, Seung Hyeon | Lee, Ju Hyeon | Kim, Kang Woong | Kim, Kyoung Duck | Jang, Ji-Won
Mercury isotope ratios in fish tissues have been used to infer sources and biogeochemical processes of mercury in aquatic ecosystems. More experimental studies are however needed to understand the internal dynamics of mercury isotopes and to further assess the feasibility of using fish mercury isotope ratios as a monitoring tool. We exposed Olive flounder (Paralichthys olivaceus) to food pellets spiked with varying concentrations (400, 1600 ng/g) of methylmercury (MeHg) and inorganic mercury (IHg) for 10 weeks. Total mercury (THg), MeHg concentrations, and mercury isotope ratios (δ²⁰²Hg, Δ¹⁹⁹Hg, Δ²⁰⁰Hg) were measured in the muscle, liver, kidney, and intestine of fish. Fish fed mercury unamended food pellets and MeHg amended food pellets showed absence of internal δ²⁰²Hg and Δ¹⁹⁹Hg fractionation in all tissue type. For fish fed IHg food pellets, the δ²⁰²Hg and Δ¹⁹⁹Hg values of intestine equilibrated to those of the IHg food pellets. Kidney, muscle, and liver exhibited varying degrees of isotopic mixing toward the IHg food pellets, consistent with the degree of IHg bioaccumulation. Liver showed additional positive δ²⁰²Hg shifts (∼0.63‰) from the binary mixing line between the unamended food pellets and IHg food pellets, which we attribute to redistribution or biliary excretion of liver IHg with a lower δ²⁰²Hg to other tissues. Significant δ²⁰²Hg fractionation in the liver and incomplete isotopic equilibration in the muscle indicate that these tissues may not be suitable for source monitoring at sites heavily polluted by IHg. Instead, fish intestine appears to be a more suitable proxy for identifying IHg sources. The results from our study are essential for determining the appropriate fish tissues for monitoring environmental sources of IHg and MeHg.
Show more [+] Less [-]The interference of nonylphenol with bacterial cell-to-cell communication Full text
2020
Jayaprada, Thilini | Hu, Jingming | Zhang, Yunyun | Feng, Huajun | Shen, Dongsheng | Geekiyanage, Sudarshanee | Yao, Yanlai | Wang, Meizhen
The interference of nonylphenol (NP) with humans and animals, especially in hormone systems, has been well-studied. There is rarely any record of its effect on bacteria, which dominate in various environments. In our study, we employed Pseudomonas aeruginosa PAO1 as a model microorganism and took its common lifestyle biofilm, mainly regulated by quorum sensing (QS), as a cut-in point to investigate the effect of NP (1, 5, 10 mg L⁻¹) on bacteria. The results showed that more than 5 mg L⁻¹ of NP did interfere with biofilm formation and affected bacterial QS. In detail, the LasI/R circuit, but not the RhlI/R circuit, was considerably obstructed. The decrease in lasI and lasR expression resulted in a significant reduction in N-3-oxo-dodecanoyl homoserine lactone (3OC₁₂-HSL) signals and the downstream production of elastases. Docking results indicated the binding of NP with LasR protein, simulating the binding of 3OC₁₂-HSL with LasR protein, which explained the obstruction of the LasIR circuit. We concluded that NP competed with 3OC₁₂-HSL and blocked 3OC₁₂-HSL binding with the LasR protein, resulting in a direct interference in bacterial biofilm formation. This is the first report of NP interference with bacterial signaling, which is not only helpful to understand the effect of NP on various ecosystems, but is also beneficial to enrich our knowledge of inter-kingdom communication.
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