Environmental polychlorinated biphenyl exposure and cytochromes P450 in raccoons (Procyon lotor)

An investigation involving raccoons as a sentinel species at the Paducah Gaseous Diffusion Plant (PGDP) and Ballard Wildlife Management Area in western Kentucky (USA) delineated the extent of exposure to polychlorinated biphenyls (PCBs). Three separate measures of hepatic cytochrome P450 (CYP) induction were used to evaluate raccoon physiological responses to PCB exposure. Hepatic CYP induction was estimated via determination of total CYP, dealkylase activities, and immunoreactive proteins. There were no differences in raccoon biomarker responses between study sites. Significant relationships between and among PCB residues and biomarkers indicated that hepatic CYP induction had occurred in response to PCB exposure. Pentoxyresorufin O-deethylase (PROD) activity, CYP1A1, and CYP1A2 were biomarkers most closely associated with PCB exposure. The rank order of responses was CYP1A1 > CYP1A2 > PROD > ethoxyresorufin O-deethylase (EROD) as related to raccoon liver PCB concentrations, whereas the order was CYP1A1 > PROD > EROD > CYP1A2 when regressed with total PCB concentrations in abdominal fat.     

Oral vaccination of raccoons (Procyon lotor) with genetically modified rabies virus vaccines

Oral vaccination is an important tool currently in use to control the spread of rabies in wildlife populations in various programs around the world. Oral rabies vaccination (ORV) of raccoons represents the largest targeted program to control wildlife rabies in the United States. Currently, the vaccinia-rabies glycoprotein recombinant virus vaccine (V-RG) is the only licensed oral rabies vaccine in the US. In the current study, captive raccoons were used to evaluate two previously described constructs of a rabies virus vaccine developed by reverse genetics (SPBNGAS and SPBNGAS-GAS) for immunogenicity and efficacy compared to the V-RG vaccine. Four of five control animals succumbed to rabies virus after severe challenge, while three of five animals vaccinated orally with SPBNGAS succumbed. No mortality was observed for animals administered SPBNGAS-GAS or the V-RG vaccine. The results of this preliminary study suggest that SPBNGAS-GAS provides comparable efficacy to V-RG. Additional studies will be needed to determine the duration of immunity and optimal dosage of SPBNGAS-GAS and to examine its efficacy in other reservoir species.     

飞灰颗粒物氧化剂产生与金属形态分布关系研究

选取了5种燃煤飞灰颗粒物,其中4种经机械燃烧产生的飞灰(编号No．1～No．4),一种手烧茶炉产生的飞灰(编号No．5),以及一种燃木产生的飞灰颗粒物(编号No．6),利用脱氧核糖法(表征颗粒物经羟自由基催化氧化生物分子能力的常用体外实验方法),考察了飞灰颗粒物上金属形态浓度与颗粒物分别在无外加络合剂及加入各种络合剂即EDTA(乙二胺四乙酸)、NTA(胺三乙酸)和CIT(柠檬酸)条件下氧化剂产生能力的关系。实验结果表明,在无外加络合剂参与下,飞灰颗粒物上氧化物键合态及有机物键合态铁与其氧化剂产生能力相关性较好。络合剂的存在对飞灰氧化能力影响与金属形态浓度相关性的影响是不同的。     

Chronic Exposure to Coal Fly Ash Causes Minimal Changes in Corticosterone and Testosterone Concentrations in Male Southern Toads Bufo terrestris

More than 50% of the electricity in the United States is produced by coal-burning power plants. The byproduct of coal-burning plants is coal fly ash, which contains increased concentrations of trace metals and is disposed of in collection basins. Southern toads (Bufo terrestris) frequently use these basins for reproduction. Male toads were collected in spring 2001 and 2002 from an ash basin and a reference site and divided into four groups: toads collected at the control site and maintained on (1) control substrate and food or (2) ash and contaminated food and toads collected at the ash site and maintained in (3) control or (4) ash conditions. Blood was collected periodically during 5 months to determine testosterone and corticosterone concentrations. Reference to ash toads exhibited a significant, transient increase in corticosterone at 4 weeks, but neither corticosterone nor testosterone continued to increase beyond this time. In contrast, toads caught and maintained on ash did not exhibit increased corticosterone. Testosterone in these toads appeared to be unrelated to ash exposure. This unexpected lack of a corticosterone response and no effect on testosterone suggests that toads chronically exposed to trace metals can acclimate to a polluted environment, but they may still experience subtle long-term consequences.     

粉煤灰吸附-Fenton氧化联合处理高浓度有机实验室废水

采用粉煤灰-Fenton氧化法联合处理高浓度有机实验室废水.在粉煤灰吸附的最佳条件下对Fenton氧化的最佳条件进行研究,考察了pH、氧化时间、H202投加量、FeS04投加量以及H202投加方式等因素对COD去除的影响.结果表明:反映时间为2h、H202投加量为0.05mL/mL、c(H202):c(FeS04)为10:1、pH为3时是最佳实验条件,此时废水COD的去除率达90%以上,色度去除率这99%以上.     

Differential Patterns of Accumulation and Retention of Dietary Trace Elements Associated With Coal Ash During Larval Development and Metamorphosis of an Amphibian

We performed an experiment in which larval gray tree frogs (Hyla chrysoscelis) were raised through metamorphosis on diets increased with a suite of elements associated with coal combustion residues (silver [Ag], arsenic [As], cadmium [Cd], chromium [Cr], copper [Cu], mercury [Hg], lead [Pb], selenium [Se], vanadium [V], and zinc [Zn]) at “low” and “high” concentrations. We quantified accumulation of metals at three life stages (mid-larval development, initiation of metamorphosis, and completion of metamorphosis) as well as effects on survival, metabolic rate, size at metamorphosis, and duration and loss of weight during metamorphosis. Most elements were accumulated in a dose-dependent pattern by some or all life stages, although this was not the case for Hg. For most elements, larval body burdens exceeded those of later life stages in some or all treatments (control, low, or high). However for Se, As, and Hg, body burdens in control and low concentrations were increased in later compared with earlier life stages. A lack of dose-dependent accumulation of Hg suggests that the presence of high concentrations of other elements (possibly Se) either inhibited accumulation or increased depuration of Hg. The duration of metamorphosis (forelimb emergence through tail resorption) was lengthened in individuals exposed to the highest concentrations of elements, but there were no other statistically significant biological effects. This study shows that patterns of accumulation and possibly depuration of metals and trace elements are complex in animals possessing complex life cycles. Further study is required to determine specific interactions affecting these patterns, in particular which elements may be responsible for affecting accumulation or retention of Hg when organisms are exposed to complex mixtures of elements.     

Organochlorine and Metal Contaminant Exposure and Effects in Hatching Black-Crowned Night Herons (Nycticorax nycticorax) in Delaware Bay

Pea Patch Island in Delaware Bay is the site of the largest heronry north of Florida. From 1989–93, the population of nine species of wading birds numbered approximately 12,000 pairs, but has recently declined to about 7,000 pairs. Because Delaware Bay is a major shipping channel and receives anthropogenic releases of toxic substances from agricultural, industrial, and municipal point and nonpoint sources, contaminant exposure and effects to the heronry have been an ongoing concern. In 1997, pipping (early hatching stage) black-crowned night herons (Nycticorax nycticorax) were collected from separate nests at Pea Patch Island and from a coastal reference site, Middle Island in Rehoboth Bay, Delaware. There was no evidence of malformations or hepatic histopathological lesions in embryos, and their body and liver weights did not differ between sites. Biomarkers of petroleum hydrocarbons, polyhalogenated contaminant, and metal exposure (cytochrome P450 induction and oxidative stress responses) did not differ (p > 0.05) between sites, although activities of benzyloxy-O-dealkylase and ethoxyresorufin-O-dealkylase were somewhat elevated in 3 of the 15 embryos collected from Pea Patch Island. Concentrations of 21 organochlorine pesticides and metabolites were relatively low at both sites, with p,p′-DDE values well below the threshold associated with eggshell thinning. Although total PCB concentration was modestly elevated (p < 0.05) in Pea Patch Island heron embryos, levels of arylhydrocarbon receptor-active PCB congeners, polychlorinated dibenzodioxins and dibenzofurans, and toxic equivalents were low and did not differ between sites. Concentrations of Cd and Mn in pipping embryos from Pea Patch Island were slightly greater (p < 0.05) than values observed in Middle Island embryos, but levels of these and the other metals and metalloids (e.g., Hg and Se) were below values associated with toxicity. In conclusion, it seems unlikely that chlorinated hydrocarbon and metal contaminant exposure constitutes a direct threat to the reproductive success of black-crowned night herons at Pea Patch Island. However, low-level exposure to these contaminants may constitute one of many stressors that in combination could adversely affect the stability of the wading bird population at this large heronry. Received: 25 October 1999/Accepted: 18 January 2000     

Trace Metal Accumulation in Trigonella foenum-graecum Irrigated with Wastewater and Human Health Risk of Metal Access Through the Consumption

Bulletin of Environmental Contamination and Toxicology - The aim of the present research was to determine the trace metal accumulations in Trigonella foenum-graecum irrigated with three different...     

双酚A对生殖健康影响的研究进展

双酚A(Bisphenol A,BPA)是一种目前普遍存在的环境化学污染物,具有内分泌干扰特性及潜在的生殖毒性,可能影响人类生殖健康。正常人群中BPA检出率高,但其对生殖健康的潜在影响是不明确的。本文主要着眼于正常人群暴露BPA对生殖健康影响的相关研究,以期为BPA暴露与生殖健康关系的研究提供参考与建议。     

Arsenic Exposure through Dietary Intake and Associated Health Hazards in the Middle East

Dietary arsenic (As) contamination is a major public health issue. In the Middle East, the food supply relies primarily on the import of food commodities. Among different age groups the main source of As exposure is grains and grain-based food products, particularly rice and rice-based dietary products. Rice and rice products are a rich source of core macronutrients and act as a chief energy source across the world. The rate of rice consumption ranges from 250 to 650 g per day per person in South East Asian countries. The source of carbohydrates through rice is one of the leading causes of human As exposure. The Gulf population consumes primarily rice and ready-to-eat cereals as a large proportion of their meals. Exposure to arsenic leads to an increased risk of non-communicable diseases such as dysbiosis, obesity, metabolic syndrome, diabetes, chronic kidney disease, chronic heart disease, cancer, and maternal and fetal complications. The impact of arsenic-containing food items and their exposure on health outcomes are different among different age groups. In the Middle East countries, neurological deficit disorder (NDD) and autism spectrum disorder (ASD) cases are alarming issues. Arsenic exposure might be a causative factor that should be assessed by screening the population and regulatory bodies rechecking the limits of As among all age groups. Our goals for this review are to outline the source and distribution of arsenic in various foods and water and summarize the health complications linked with arsenic toxicity along with identified modifiers that add heterogeneity in biological responses and suggest improvements for multi-disciplinary interventions to minimize the global influence of arsenic. The development and validation of diverse analytical techniques to evaluate the toxic levels of different As contaminants in our food products is the need of the hour. Furthermore, standard parameters and guidelines for As-containing foods should be developed and implemented.     

Effects of Cadmium Exposure on Metal Accumulation and Energy Metabolism of Silver Carp (<Emphasis Type="Italic">Hypophthalmichthys molitrix</Emphasis>)

Effects of cadmium (Cd) exposure on metal accumulation and energy metabolism of silver carp (Hypophthalmichthys molitrix) were studied during 14 days. The results showed that Cd accumulated in tissues of silver carp significantly with time and Cd concentration, as the order: liver?>?kidney?>?gill?>?muscle. The levels of muscle glycogen, triglyceride, and plasma triglyceride decreased significantly (p?<?0.05). The levels of muscle protein, plasma glucose and lactate significantly increased during the first 8 days, and then all significantly decreased (p?<?0.05). No significant alternations were observed in muscle cortisol, ATP and plasma protein (p?>?0.05). The results indicate that the tissues’ Cd concentrations and energy metabolism were altered by the presence of waterborne Cd, and silver carp mobilizes the muscle energy stores to cope with the increased energy demands for detoxication and repair mechanism induced by the exposure to waterborne Cd.     

Species-Specific (Hyalella azteca and Lymnea stagnalis) Dietary Accumulation of Gold Nano-particles Associated with Periphyton

Bulletin of Environmental Contamination and Toxicology - Ecological effects of gold nano-particles (AuNP) are examined due to growing use in consumer and industrial materials. This study...     

Potentially Toxic Metal Accumulation in Spinach (Spinacia oleracea L.) Irrigated with Industrial Wastewater and Health Risk Assessment from Consumption

This study aimed to determine the potentially toxic metal contents in soil and spinach samples in areas irrigated with industrial wastewater and to evaluate the potentially toxic metal accumulation in spinach samples according to pollution indices. Water, soil and spinach samples were analysed using atomic absorption spectrophotometer (Perkin-Elmer AAS-300). In this study, it was determined that the potentially toxic metal values ??in the spinach samples irrigated with groundwater and sugar industry wastewater varied between 1.59 and 1.84, 0.22–0.68, 0.56–1.14, 1.41–1.56, 1.62–3.23, 0.57–1.02, 0.86–1.33, 0.20–0.32 and 0.35–2.10 mg/kg for Cd, Co, Cr, Cu, Fe, Ni, Pb, Zn and Mn, respectively. It was concluded that the difference between the metal values ??in the spinach samples according to the irrigation sources was statistically significant, except for Cu and Pb (p?>?0.05). According to the results of this study, there is no health risk for Pb, Co and Cr with HRI values ??below 1.0, while there is a risk for Cd, Cu, Fe, Ni, Mn and Zn. The much higher HRI values ??of Cd than 1 (196.8 and 169.6) suggested that this metal is likely to cause significant health problems in the region.