Effects of sodium arsenate exposure on liver fatty acid profiles and oxidative stress in rats

The present study aimed to evaluate the effect of arsenic on liver fatty acids (FA) composition, hepatotoxicity and oxidative status markers in rats. Male rats were randomly devised to six groups (n?=?10 per group) and exposed to sodium arsenate at a dose of 1 and 10 mg/l for 45 and 90 days. Arsenate exposure is associated with significant changes in the FA composition in liver. A significant increase of saturated fatty acids (SFA) in all treated groups (p?<?0.01) and trans unsaturated fatty acids (trans UFA) in rats exposed both for short term for 10 mg/l (p?<?0.05) and long term for 1 and 10 mg/l (p?<?0.001) was observed. However, the cis UFA were significantly decreased in these groups (p?<?0.05). A markedly increase of indicator in cell membrane viscosity expressed as SFA/UFA was reported in the treated groups (p?<?0.001). A significant increase in the level of malondialdehyde by 38.3 % after 90 days of exposure at 10 mg/l was observed. Compared to control rats, significant liver damage was observed at 10 mg/l of arsenate by increasing plasma marker enzymes after 90 days. It is through the histological investigations in hepatic tissues of exposed rats that these damage effects of arsenate were confirmed. The antioxidant perturbations were observed to be more important at groups treated by the high dose (p?<?0.05). An increase in the level of protein carbonyls was observed in all treated groups (p?<?0.05). The present study provides evidence for a direct effect of arsenite on FA composition disturbance causing an increase of SFA and TFAs isomers, liver dysfunction and oxidative stress. Therefore, arsenate can lead to hepatic damage and propensity towards liver cancer.     

Heavy metal exposure in large game from a lead mining area: Effects on oxidative stress and fatty acid composition in liver

The Pb mining area of the valley of Alcudia and the Sierra Madrona mountains (S. Spain) has been exploited intermittently for over 2100 years, since Roman occupation and up until the late 1900s. Red deer (n = 168) and wild boar (n = 58) liver and bone (metacarpus) were analyzed for Pb, Zn, Cu, Cd, As and Se. Lipid peroxidation, total and oxidized glutathione (GSH), superoxide dismutase (SOD), GSH peroxidase (GPX) and fatty acid composition were studied in liver of red deer. The concentrations of Pb in liver and bone of red deer and wild boar were higher in the mining area than in the control area, and higher in the wild boar than red deer, but well below the level associated with clinical signs of Pb poisoning. Liver levels of Cu, Cd and Se were also higher in red deer from the mining area. Red deer from the mining area had 39% less total GSH than in the control area. The percentage of docosahexaenoic acid in liver of red deer from the mining area was 16% lower than in the control area.     

Volatile organohalogen compounds in human urine: the effect of environmental exposure

The paper presents the results of determination of volatile organohalogen compounds (VOX) in urine samples from subjects exposed to these compounds in their workplaces and through consumption of chlorinated tap water. The analytes were isolated and preconcentrated from the complex urine samples using the thin layer headspace (TLHS) technique with autogenous generation of the liquid sorbent. Final gas chromatographic determination was carried out by direct aqueous injection with electron capture detection (DAI-ECD). The results indicate that only a small fraction (<4%) of the VOX input is excreted with urine in the non-metabolized form. A positive correlation was found between the occupational levels of VOX in the workplace and their levels in urine. VOX levels in the urine of subjects not exposed to them in the workplace were significantly lower. Their presence in the organisms was most probably related to consumption of tap water produced by chlorination of surface waters.     

Chronic copper exposure and fatty acid composition of the amphipod Dikerogammarus villosus: results from a field study

Field study allows assessment of long-term effects on fatty acid (FA) composition of organisms under chronic exposure to metals. One expected effect of copper is peroxidation of lipids and essentially polyunsaturated fatty acids (PUFA). FA analysis was established for the amphipod Dikerogammarus villosus subjected to different degrees of copper exposure (4–40 μg Cu L⁻¹). A previous study in our team showed that this species regulates its body Cu concentration (106–135 mg Cu kg⁻¹ dry weight). Despite the high capacity of bioaccumulation, the absence of a correlation between copper concentration in D. villosus and water prevents its use as bioindicator of copper pollution. Both sexes from the most polluted site showed the lowest total FA content, but the highest PUFA percent, mainly of the long-chained variety (C20–C22). Mechanisms leading to the prevention of lipid peroxidation in this species were discussed (metallothioneins and intracellular granules) and proposed with support from literature data.     

The association between prenatal exposure to polycyclic aromatic hydrocarbons and childhood intelligence: a systematic review of observational studies

Environmental Science and Pollution Research - Exposure to polycyclic aromatic hydrocarbons (PAHs) during pregnancy has been associated with many adverse child health. However, the evidence on such...     

Guarana improves behavior and inflammatory alterations triggered by methylmercury exposure: an in vivo fruit fly and in vitro neural cells study

Environmental Science and Pollution Research - Methylmercury (MeHg) is a well-known environmental pollutant associated with neurological and developmental deficits in animals and humans. However,...     

Dietary arsenic consumption and urine arsenic in an endemic population: response to improvement of drinking water quality in a 2-year consecutive study

We assessed the association between arsenic intake through water and diet, and arsenic levels in first morning-void urine under variable conditions of water contamination. This was done in a 2-year consecutive study in an endemic population. Exposure of arsenic through water and diet was assessed for participants using arsenic-contaminated water (≥50 μg L^?1) in a first year (group I) and for participants using water lower in arsenic (<50 μg L^?1) in the next year (group II). Participants with and without arsenical skin lesions were considered in the statistical analysis. Median dose of arsenic intake through drinking water in groups I and II males was 7.44 and 0.85 μg kg body wt.^?1 day^?1 (p <0.0001). In females, it was 5.3 and 0.63 μg kg body wt.^?1 day^?1 (p <0.0001) for groups I and II, respectively. Arsenic dose through diet was 3.3 and 2.6 μg kg body wt.^?1 day^?1 (p?=?0.088) in males and 2.6 and 1.9 μg kg body wt.^?1 day^?1 (p?=?0.0081) in females. Median arsenic levels in urine of groups I and II males were 124 and 61 μg L^?1 (p?=?0.052) and in females 130 and 52 μg L^?1 (p?=?0.0001), respectively. When arsenic levels in the water were reduced to below 50 μg L^?1 (Indian permissible limit), total arsenic intake and arsenic intake through the water significantly decreased, but arsenic uptake through the diet was found to be not significantly affected. Moreover, it was found that drinking water mainly contributed to variations in urine arsenic concentrations. However, differences between male and female participants also indicate that not only arsenic uptake, but also many physiological factors affect arsenic behavior in the body and its excretion. As total median arsenic exposure still often exceeded 3.0 μg kg body wt.^?1 day^?1 (the permissible lower limit established by the Joint Expert Committee on Food Additives) after installation of the drinking water filters, it can be concluded that supplying the filtered water only may not be sufficient to minimize arsenic availability for an already endemic population.     

Disinfection of an advanced primary effluent with peracetic acid and ultraviolet combined treatment: a continuous-flow pilot plant study

Disinfection of an advanced primary effluent using a continuous-flow combined peracetic acid/ultraviolet (PAA/UV) radiation system was evaluated. The purpose was to determine whether the maximum microbial content, established under Mexican standards for treated wastewaters meant for reuse--less than 240 most probable number fecal coliforms (FC)/100 mL--could be feasibly accomplished using either disinfectant individually, or the combined PAA/UV system. This meant achieving reduction of up to 5 logs, considering initial concentrations of 6.4 x 10(+6) to 5.8 x 10(+7) colony forming units/100 mL. During the tests performed under these experiments, total coliforms (TC) were counted because FC, at the most, will be equal to TC. Peracetic acid disinfection achieved less than 1.5 logs TC reduction when the C(t) x t product was less than 2.26 mg x minimum (min)/L; 3.8 logs for C(t) x t 4.40 mg x min/L; and 5.9 logs for C(t) x t 24.2 mg x min/L. In continuous-flow UV irradiation tests, at a low-operating flow (21 L/min; conditions which produced an average UV fluence of 13.0 mJ/cm2), the highest TC reduction was close to 2.5 logs. The only condition that produced a disinfection efficiency of approximately 5 logs, when both disinfection agents were used together, was the combined process dosing 30 mg PAA/L at a pilot plant flow of 21 L/min and contact time of 10 minutes to attain an average C(t) x t product of 24.2 mg x min/L and an average UV fluence of 13 mJ/cm2. There was no conclusive evidence of a synergistic effect when both disinfectants were employed in combination as compared to the individual effects achieved when used separately, but this does not take into account the nonlinearity (tailing-off) of the dose-response curve.     

Genotoxicity of organic extracts of urban airborne particulate matter: an assessment within a personal exposure study

Airborne particulate matter, PM(10) and PM(2.5), are associated with a range of health effects including lung cancer. Their complex organic fraction contains genotoxic and carcinogenic compounds such as polycyclic aromatic hydrocarbons (PAHs) and their derivatives. This study evaluates the genotoxicity of the PM(10) and PM(2.5) organic extracts that were sampled in the framework of a personal exposure study in three French metropolitan areas (Paris, Rouen and Strasbourg), using the comet assay, performed on HeLa S3 cells. In each city, 60-90 non-smoking volunteers composed of two groups of equal size (adults and children) carried the personal Harvard Chempass multi-pollutant sampler during 48h along two different seasons ('hot' and 'cold'). Volunteers were selected so as to live (home and work/school) in 3 different urban sectors contrasted in terms of air pollution within each city (one highly exposed to traffic emissions, one influenced by local industrial sources, and a background urban environment). Genotoxic effects are stronger for PM(2.5) extracts than for PM(10), and greater in winter than in summer. Fine particles collected by subjects living within the traffic proximity sector present the strongest genotoxic responses, especially in the Paris metropolitan area. This work confirms the genotoxic potency of particulate matter (PM(10) and PM(2.5)) organic extracts to which urban populations are exposed.     

Chronic toxicity of arsenic, cobalt, chromium and manganese to Hyalella azteca in relation to exposure and bioaccumulation

Chronic toxicity of As, Co, Cr and Mn to Hyalella azteca can be described using a saturation-based mortality model relative to total-body or water metal concentration. LBC25s (total-body metal concentrations resulting in 25% mortality in 4 weeks) were 125, 103, 152 and 57,900 nmol g-1 dry weight for As, Co, Cr and Mn respectively. LC50s (metal concentrations in water resulting in 25% mortality in 4 weeks) were 5600, 183, 731, and 197,000 nmol L-1, respectively. A hormesis growth response to As exposure was observed. Growth was a more variable endpoint than mortality for all four toxicants; however, confidence limits based on growth and mortality all overlapped, except Cr which had no effect on growth. Mn toxicity was greater in glass test containers compared to plastic. Bioaccumulation of As, Co, Cr, and Mn was strongly correlated with, and is useful for predicting, chronic mortality.     

Internal exposure to pollutants measured in blood and urine of Flemish adolescents in function of area of residence

The Centre for Environment and Health in Flanders, the Northern part of Belgium, started a biomonitoring program on adolescents in 2003. 1679 adolescents residing in nine areas with different patterns of pollution participated in the study. Possible confounding effects of lifestyle and personal characteristics were taken into account. The geometric mean levels of cadmium and lead in whole blood amounted to 0.36 and 21.7 microg l(-1), those of PCBs, DDE and HCB in serum to 68, 94 and 20.9 ng g(-1) fat, and those of 1-hydroxypyrene and t,t'-muconic acid in urine to 88 ng g(-1) creatinine and 72 microg g(-1) creatinine. Significant regional differences in internal lead, cadmium, PCBs, DDE and HCB exposure were observed in function of area of residence, even after adjustment for age, sex, smoking (and body mass index for the chlorinated compounds). Compared to a reference mean, internal exposure was significantly higher in one or more of the areas: Cd and Pb in the Antwerp agglomeration, Cd in the Antwerp harbour, PCBs in the Ghent agglomeration, PCBs, DDE and HCB in the Ghent harbour, Cd, PCBs, DDE and HCB in the rural area, DDE in Olen and in the Albert canal areas. Adolescents living in an area with intensive fruit cultivation (showing overall the lowest values) and, surprisingly, in areas around household waste incinerators (average of six areas), had no significantly increased internal exposures. Subjects from separate areas around waste incinerators showed significant differences in body load of various environmental contaminants.     

改性沸石去除地下水中铁锰实验研究

测定了2种改性沸石的基本特性,并选取0.6 m层高的交换柱,通过动态试验,研究其分别用于除铁和除锰的工艺性能。实验结果表明,2种沸石质量全交换容量分别为578.2 mmol/kg和722.2 mmol/kg;产水水质均能达到饮用水标准：含铁量≤0.3 mg/L,含锰量≤0.1 mg/L;减少进水中铁锰含量（≤2 mg/L）和降低运行流速（≤20 m/h）,都有利于提高工作交换容量,但流速对除铁沸石影响较小;再生剂为1 mol/L的NaCl,再生速率1 m/h条件下,每升除铁沸石再生剂用量为1.2 L,洗脱率（再生废液中目标离子含量与原水中过滤时的去除量之比）达0.95,比耗（再生剂用量与工作交换容量之比）为16,每升除锰沸石再生剂用量为1.6 L,洗脱率达0.8,比耗为16。     

Bioavailability in soil or sediment: exposure of different organisms and approaches to study it

Soil and benthic organisms may be exposed to contaminants via different routes: (pore) water, soil or sediment, and food. Depuration of the contaminant from the organisms may take place via the same routes and, additionally, via biotransformation, reproduction, etc. Whereas uptake from and depuration to water can be predicted well, predictions for soil or sediment are less accurate. One of the reasons may be the reduced bioavailability of the contaminant in the soil or sediment. In biomimetic approaches, such as solid phase micro-extraction (SPME) or measurements with C18-discs, the freely dissolved concentration in the (pore) water is determined. The SPME-fiber or C18-disc may serve as a surrogate organism, but sometimes underestimates, and sometimes overestimates bioavailability. The soil (or sediment) availability ratio (SARA) method, that uses organisms to study the uptake of freshly added and 'aged' chemicals, is proposed to study the magnitude of the reduction in bioavailability. SARA also includes the organism-specific exposure and depuration routes.     

Effect of acute exposure to PFOA on mouse liver cells in vivo and in vitro

Increasingly, epidemiological evidences indicate chemosynthetic perfluorooctanoic acid (PFOA), an environmental pollutant, induces potential adverse effect on human health after long-term exposure. However, less study has been performed for assessment of acute effect of PFOA exposure on metabolic homeostasis. In experimental designs, PFOA-exposed liver cells in vivo and in vitro were used to discuss underlying mechanism related to PFOA-induced metabolic dysfunction. In serological tests, PFOA-exposed mice showed increased treads of liver functional enzymes in alanine transaminase (ALT), aspartate transaminase (AST), and total bilirubin (T-BIL), trypsinase, low density lipoprotein-cholesterol (LDL-C), and insulin, while blood glucose, high density lipoprotein-cholesterol (HDL-C), and glucagon levels were reduced. In histocytological observations, PFOA-exposed liver showed visible cytoplasmic vesicles, and intact pancreatic islets were observed in PFOA-exposed pancreas. Additionally, increased insulin-positive cells and reduced glucagon-positive cells were detected in PFOA-exposed islets. As shown in immunoassays, PFOA-exposed liver resulted in elevations of cluster of differentiation 36 (CD36)-labeled cells and CD36 protein. In mouse liver cell study, PFOA-exposed cells showed increased cell apoptotic count, and increased phosphorylated levels of Bcl-2 and Bad in the cells. Furthermore, PFOA-exposed liver cells exhibited elevations of CD36-labeled cells and CD36 protein. Taken together, the present data demonstrate that acute exposure to PFOA-impaired liver function is associated with inducting CD36 expression and apoptosis, as well as disrupting key hormones in the pancreas.     

The association between diazinon exposure and dyslipidemia occurrence: a systematic and meta-analysis study

Environmental Science and Pollution Research - The effects of diazinon (DZN), an organophosphate pesticide, on lipid profiles have been extensively reported. However, controversy on this issue...     

Radon exposure and risk of cerebrovascular disease: a systematic review and meta-analysis in occupational and general population studies

Environmental Science and Pollution Research - Although it is biologically plausible, findings relating radon exposure to the risk of cerebrovascular disease (CeVD) are inconsistent and...