Chromium: a review of environmental and occupational toxicology

The following topics are covered in this brief review on the environmental and occupational toxicology of chromium: occurrence, production and uses of chromium and chromium compounds; experimental toxicology; chromium toxicity for man; hygienic and ecologic aspects of chromium contamination of the environment. The review provides a conclusive evidence which suggests that chromium, especially its hexavalent form, is both toxic and carcinogenic, but its trivalent form is physiologically essential in the metabolism of insulin. It is also emphasized that among the major sources of environmental chromium today are the cement industry and the increasingly widespread use of chromium compounds added as an anticorrosion admixture to a variety of cooling systems, e.g. in large power plants, which may greatly contribute to the overall pollution of outdoor air at the sites.     

Cancer-producing substances

Resume It is demonstrated that the cancer-producing substances contain particles of carbon, metals or polymerised compounds, all having surface-electrons, and it is made assumptive that products having a low energy of ionisation are able to deactivate the carcinogenic particles and also to repress malignant growth.In the interest of the public health the combustion in the internal combustion engine should be made more complete and the use of lead compounds as anti-knock agents should be prohibited. Further, all food products manufactured in a manner able to produce carcinogenic particles should be treated with deactivating agents or the treatments causing the production of the particles should be prohibited.     

Hygienic and toxicological aspects of occupational and environmental exposure to beryllium

As the production of missile, nuclear devices and electronics grew and modern industrial technologies emerged the risk of the occupational exposure to beryllium has become increasingly common and widespread. The environmental burden of beryllium is also on the increase, not only as a result of emissions from plants producing and processing beryllium, or its alloys and compounds, but also from burning coal of higher beryllium content in some localities. This article discusses primarily the hygienic and toxicologic aspects of beryllium and its threat to human health. The following topics are included in this review: occurrence, production and uses of beryllium; its metabolism and experimental toxicology; clinical toxicology and pathogenesis of berylliosis; hygienic and epidemiologic aspects of berylliosis; berylliosis treatment and prevention. Berylliosis is here characterized as a disease combining clinical manifestations of pneumosclerosis, allergy to beryllium and, in its granulomatous form, autoimmune reactions. Importantly, the available technical means and measures can ensure that the both occupational and environmental exposure to beryllium can be kept below the established MAC values. If occasionally impossible, special preventive measures should be adopted. It is essential that all persons with allergy be prophylactically excluded from work at risk of exposure to beryllium.     

Distribution and health risk assessment of heavy metals in soil surrounding a lead and zinc smelting plant in Zanjan,Iran

One of the problematic issues in soil pollution studies is heavy metal particles which are produced by mines and smelting units and spread through wind action and/or runoff. Pollution and health risk assessment of cadmium, lead, zinc, copper, and nickel in soil around the lead and zinc smelting factory was carried out in Zanjan City, Iran. Contamination factor (Cf), pollution load index (PLI), geoaccumulation index (Igeo), hazard quotient (HQ), hazard index (HI), and carcinogenic risk were pollution and human health risk assessment metrics in this study. Based on the Iranian soil guideline value, soil samples in the studied areas were contaminated the least by copper and nickel and the most by cadmium. PLI results showed that soils near the production line were heavily or extremely heavily polluted. The results of Cf and Igeo showed that lead and zinc were the most important contaminants. Health risk assessment indicated that lead and cadmium in soil were the main contaminants, which pose both carcinogenic and non-carcinogenic risks to human health; carcinogenic risk levels were unacceptably high (above 1 × 10^?4). It can be concluded that mining and smelting activities degrade soil quality in this region and the soil pollution might be extended to farming areas.     

Metabolic engineering strategies for improving xylitol production from hemicellulosic sugars

Xylitol is a five-carbon sugar alcohol with potential for use as a sweetener. Industrially, xylitol is currently produced by chemical hydrogenation of d-xylose using Raney nickel catalysts and this requires expensive separation and purification steps as well as high pressure and temperature that lead to environmental pollution. Highly efficient biotechnological production of xylitol using microorganisms is gaining more attention and has been proposed as an alternative process. Although the biotechnological method has not yet surpassed the advantages of chemical reduction in terms of yield and cost, various strategies offer promise for the biotechnological production of xylitol. In this review, the focus is on the most recent developments of the main metabolic engineering strategies for improving the production of xylitol.     

Exposure to MTBE and Acute Human Health Effects: A Critical Literature Review

Whether use of oxygen-rich gasoline additives to reduce air pollution is a cause of acute adverse health effects is an ongoing concern in the United States. Attention has focused in particular on use of methyl tert-butyl ether (MTBE, CAS #1634-04-4) and, despite considerable published research, debate persists regarding its potential for adverse health effects. To better understand the debate, we critically reviewed published and unpublished reports to assess whether differences in methodological approach or quality could explain the variable results reported. We considered studies on acute human health effects of inhalation exposure to MTBE either alone or in gasoline (19 reports) as well as clinical use of parenteral MTBE to dissolve cholesterol gall stones (12 reports). Each study was reviewed from three perspectives (epidemiology, industrial hygiene, and, clinical diagnostics), judged satisfactory, limited adequacy, or unsatisfactory for each criterion, and grouped into one of three categories from most to least adequate in overall methodology. The studies judged most adequate on individual criteria and those with highest overall adequacy found no significant association between MTBE exposure and symptoms. We propose that the persistent debate has been fueled by the findings of methodologically weak hypothesis-generating studies.     

Life Cycle Assessment of Diesel and Electric Public Transportation Buses

The Clean Air Act in the United States identifies diesel‐powered motor vehicles, including transit buses, as significant sources of several criteria pollutants that contribute to ground‐level ozone formation or smog. The effects of air pollution in urban areas are often more significant due to congestion and can lead to respiratory and cardiovascular health impacts. Life cycle assessment (LCA) has been utilized in the literature to compare conventional gasoline‐powered passenger cars with various types of electric and hybrid‐powered alternatives, however, no similarly detailed studies exist for mass transit buses. LCA results from this study indicate that the use phase, consisting of diesel production/combustion for the conventional bus and electricity generation for the electric bus, dominates most impact categories; however, the effects of battery production are significant for global warming, carcinogens, ozone depletion, and eco‐toxicity. There is a clear connection between the mix of power‐generation technologies and the preference for the diesel or electric bus. With the existing U.S. average grid, there is a strong preference for the conventional diesel bus over the electric bus when considering global warming impacts alone. Policy makers must consider regional variations in the electricity grid prior to recommending the use of battery electric buses to reduce carbon dioxide (CO₂) emissions. This study found that the electric bus was preferable in only eight states, including Washington and Oregon. Improvements in battery technology reduce the life cycle impacts from the electric bus, but the electricity grid makeup is the dominant variable.     

Recent advances in exploiting goat's milk: Quality,safety and production aspects

Goat milk production is a dynamic and growing industry that is fundamental to the wellbeing of hundreds of millions of people worldwide and is an important part of the economy in many countries. The aim of the present review is to provide an integrated and critical analysis of the major aspects in this field to highlight unexploited nutritional potential of goat milk and the need for improvements, particularly in food safety. First, it should be kept in mind that goat milk like cow milk delivers many nutrients with relatively low energy content, and is relevant to the health of consumers throughout the life cycle. In addition, the review presents data suggesting that goat milk possesses many advantages over cow milk, for use as a nutritional source for infants and children and as a medicinal food. Furthermore, goats, by consuming large amounts of natural browsing plants all year around, are a potentially overlooked “treasure trove”, with respect to health promoting components. The survey suggests that total bacterial count that is currently used as the major quality measure to prevent pathogen-related food toxicity is not sufficiently effective. The proposal is to include somatic cell count as a routine criterion to qualify the hygienic status of goat milk in terms of the relevant physiology and biochemistry. The paper presents a novel mechanism controlling milk secretion, and demonstrates the use of this knowledge in making decisions for two major managerial tasks that farmers face, namely milking frequency that dictates to a large extent the milk yield and workload on the farm, and helping to deal with subclinical mastitis that is the single major cause for economical losses in dairy farms worldwide.     

Pig proteomics: a review of a species in the crossroad between biomedical and food sciences

The pig (Sus scrofa) is one of the most important animal species used for meat production worldwide, playing a fundamental role in numerous cultures from Southern Europe to the Pacific Islands. Additionally, it is broadly used as an experimental animal for several purposes, from physiological studies to drug testing and surgical training. Proteomics studies have covered both physiological and biomedical application studies of pig to a much greater extent than for any other farm animal. Despite this fact, no review seems to be available on the application of proteomics to production aspects in pig. The aim of this article is to provide a review on such applications of proteomics to the pig species. The article is divided in three parts. The first is dedicated to productive characterization and includes aspects related to reproduction and meat science. The second concerns the management of health and disease in production. Finally, the third part concerns the use of the pig as a model organism in biomedical research.     

Review: Animal health and sustainable global livestock systems

This paper discusses the sustainability of livestock systems, emphasising bidirectional relations with animal health. We review conventional and contrarian thinking on sustainability and argue that in the most common approaches to understanding sustainability, health aspects have been under-examined. Literature review reveals deep concerns over the sustainability of livestock systems; we recognise that interventions are required to shift to more sustainable trajectories, and explore approaches to prioritising in different systems, focusing on interventions that lead to better health. A previously proposed three-tiered categorisation of ‘hot spots’, ‘cold spots’ and ‘worried well’ animal health trajectories provides a mental model that, by taking into consideration the different animal health status, animal health risks, service response needs and key drivers in each system, can help identify and implement interventions. Combining sustainability concepts with animal health trajectories allows for a richer analysis, and we apply this to three case studies drawn from North Africa and the Middle East; Bangladesh; and the Eastern Cape of South Africa. We conclude that the quest for sustainability of livestock production systems from the perspective of human and animal health is elusive and difficult to reconcile with the massive anticipated growth in demand for livestock products, mainly in low- and middle-income countries, as well as the aspirations of poor livestock keepers for better lives. Nevertheless, improving the health of livestock can contribute to health sustainability both through reducing negative health impacts of livestock and increasing efficiency of production. However, the choice of the most appropriate options must be under-pinned by an understanding of agro-ecology, economy and values. We argue that a new pillar of One Health should be added to the three traditional sustainability pillars of economics, society and environment when addressing livestock systems.     

农用化学品污染及预防建议

农用化学品是农业生产的重要组成部分,其安全问题也成为人们关注的焦点。农用化学品可分为化肥、农药、农膜3类。化肥主要用于提高土壤肥力,增加农作物产量,不合理使用则会改变土壤性质,降低土壤肥力,并且对生态环境以及人类健康造成不可忽视的危害。农药主要用于杀菌、杀虫、除草等,在促进和保障农作物健康生长中发挥重要作用,但农药的滥用造成农药事故频发,农药的毒性富集作用以及残留问题越发引起人们的关注。农膜主要用于农膜覆盖栽培技术,农膜的原料主要是聚乙烯树脂等高分子化学物质,在土壤中很难降解,造成的环境污染问题日益突出。各种农用化学品的不合理使用,可降低农产品的质量,使其在出口贸易中受到极大限制,造成巨大的经济损失。本文在肯定农用化学品在现代化农业生产中的巨大贡献的同时,深入分析了其污染状况及危害,总结了当前国际上对于化肥、农药、农膜的研究进展以及所取得的成果,最后提出了科学使用农用化学品的建议。     

The Industrial Ecology of Lead and Electric Vehicles

The lead battery has the potential to become one of the first examples of a hazardous product managed in an environmentally acceptable fashion. The tools of industrial ecology are helpful in identifying the key criteria that an ideal lead-battery recycling system must meet maximal recovery of batteries after use, minimal export of used batteries to countries where environmental controls are weak, minimal impact on the health of communities near lead-processing facilities, and maximal worker protection from lead exposure in these facilities. A well-known risk analysis of electric vehicles is misguided, because it treats lead batteries and lead additives in gasoline on the same footing and implies that the lead battery should be abandoned. The use of lead additives in gasoline is a dissipative use where emissions cannot be confined: the goal of management should be and has been to phase out this use. The use of lead in batteries is a recyclable use, because the lead remains confined during cycles of discharge and recharge. Here, the goal should be clean recycling. The likelihood that the lead battery will provide peaking power for several kinds of hybrid vehicles-a role only recently identified increases the importance of understanding the levels of performance achieved and achievable in battery recycling. A management system closely approaching clean recycling should be achievable.     

Beyond microbial community composition: functional activities of the oral microbiome in health and disease

The oral microbiome plays a relevant role in the health status of the host and is a key element in a variety of oral and non-oral diseases. Despite advances in our knowledge of changes in microbial composition associated with different health conditions the functional aspects of the oral microbiome that lead to dysbiosis remain for the most part unknown. In this review, we discuss the progress made towards understanding the functional role of the oral microbiome in health and disease and how novel technologies are expanding our knowledge on this subject.     

Health and Welfare in Organic Poultry Production

This review paper deals with the major health and welfare aspects of organic poultry production. The differences between organic and conventional egg and poultry meat production are discussed, with the main emphasis on housing and management requirements, feed composition and the use of veterinary prophylactic and therapeutic drugs. The effects of the legislation and statutes for organic farming on the health and welfare of the birds are also discussed, especially in relation to the biosecurity problems associated with free-range systems, the occurrence of behavioural disturbances in loose housed flocks and the use of veterinary drugs and vaccinations in general. The results from a questionnaire sent out to all Swedish organic egg producers, where questions about the farmer's perception of the birds' health status were included, are presented at the end of the paper. It is concluded that most of the health and welfare problems seen in conventional poultry systems for loose housed or free ranging birds can also been found on organic poultry farms. It is also concluded that there is a need for information about biosecurity, disease detection and disease prevention on organic poultry farms.     

Rapid evolutionary loss of metal resistance revealed by hatching decades‐old eggs

We investigated the evolutionary response of an ecologically important freshwater crustacean, Daphnia, to a rapidly changing toxin environment. From the 1920s until the 1960s, the use of leaded gasoline caused the aquatic concentration of Pb to increase at least fivefold, presumably exerting rapid selective pressure on organisms for resistance. We predicted that Daphnia from this time of intense pollution would display greater resistance than those hatched from times of lower pollution. This question was addressed directly using the resurrection ecology approach, whereby dormant propagules from focal time periods were hatched and compared. We hatched several Daphnia genotypes from each of two Swiss lakes, during times of higher (1960s /1980s) and lower (2000s) lead stress, and compared their life histories under different laboratory levels of this stressor. Modern Daphnia had significantly reduced fitness, measured as the population growth rate (λ), when exposed to lead, whereas those genotypes hatched from times of high lead pollution did not display this reduction. These phenotypic differences contrast with only slight differences measured at neutral loci. We infer that Daphnia in these lakes were able to rapidly adapt to increasing lead concentrations, and just as rapidly lost this adaptation when the stressor was removed.     

Trade‐offs across productivity,GHG intensity,and pollutant loads from second‐generation sorghum bioenergy

Greenhouse gas (GHG) intensity is frequently used to assess the mitigation potential of biofuels; however, failure to quantify other environmental impacts may result in unintended consequences, effectively shifting the environmental burden of fuel production rather than reducing it. We modeled production of E₈₅, a gasoline/ethanol blend, from forage sorghum (Sorghum bicolor cv. photoperiod LS) grown, processed, and consumed in California's Imperial Valley in order to evaluate the influence of nitrogen (N) management on well‐to‐wheel (WTW) environmental impacts from cellulosic ethanol. We simulated 25 N management scenarios varying application rate, application method, and N source. Life cycle environmental impacts were characterized using the EPA's criteria for emissions affecting the environment and human health. Our results suggest efficient use of N is an important pathway for minimizing WTW emissions on an energy yield basis. Simulations in which N was injected had the highest nitrogen use efficiency. Even at rates as high as 450 kg N ha^?1, injected N simulations generated a yield response sufficient to outweigh accompanying increases in most N‐induced emissions on an energy yield basis. Thus, within the biofuel life cycle, trade‐offs across productivity, GHG intensity, and pollutant loads may be possible to avoid at regional to global scales. However, trade‐offs were seemingly unavoidable when impacts from E₈₅ were compared to those of conventional gasoline. The GHG intensity of sorghum‐derived E₈₅ ranged from 29 to 44 g CO₂ eq MJ^?1, roughly 1/3 to 1/2 that of gasoline. Conversely, emissions contributing to local air and water pollution tended to be substantially higher in the E₈₅ life cycle. These adverse impacts were strongly influenced by N management and could be partially mitigated by efficient application of N fertilizers. Together, our results emphasize the importance of minimizing on‐farm emissions in maximizing both the environmental benefits and profitability of biofuels.     

Comparative Study of Blood Lead Levels in Uruguayan Children (1994–2004)

Lead does not fulfill any physiological function in the human body. It is generally accepted that the blood lead level (BLL) is the best exposure index, as there is an excellent correlation between the actual exposure of the individual and the concentration of lead in blood. In Uruguay, lead contamination becomes a matter of public concern in 2001, giving rise to a sensitization in the population, which in many cases brought about a change in hygienic and dietary habits of the children. In 2004, after the leaded gasoline phasing out process in Uruguay was completed, we studied non-exposed children to correlate BLL with variables such as age, sex, area of residence, and available environmental lead data and compared these results with those from our similar screening studies 10years ago. The main result of this comparison is that BLL from children in our country had a significant decrease between 1994 and 2004.     

微生物在生物能源生产中的应用(英文)

生物可再生能源是最有前景的石油替代品之一.生物能源的生产原料包括:植物、有机废弃物和微生物.微生物在生物能源生产上有着广泛的应用,利用微生物制备的主要生物能源包括:生物柴油、生物乙醇、生物甲烷等.某些微生物如微藻和真菌可以生产大量油脂,这些油脂可以转化为生物柴油;有些微生物如酵母可以将糖类、淀粉以及纤维素转化为燃料乙醇,添加乙醇的汽油或柴油燃烧排放明显降低;还有些厌氧微生物可以将有机废弃物转化为甲烷,可用做家用燃气、车用燃气或发电.除此之外微生物还具有在生产能源的同时治理环境污染的优势.总之研究开发微生物在生物能源生产中的应用有利于世界可持续发展.     

Antichaperone activity and heme degradation effect of methyl tert‐butyl ether (MTBE) on normal and diabetic hemoglobins

Because of the extensive use of methyl tert‐butyl ether (MTBE) as an additive to increase the octane quality of gasoline, the environmental pollution by this compound has increased in recent decades. Environmental release of MTBE may lead to its entry to the blood stream through inhalation or drinking of contaminated water, and its interactions with biological molecules such as proteins. The present study was proposed to comparatively investigate the interactions of MTBE with hemoglobin (Hb) from diabetic and nondiabetic individuals using various spectroscopic methods including UV‐visible, fluorescence, chemiluminescence, and circular dichroism. These results demonstrated the effects of MTBE on heme degradation of Hb and the reaction of these degradation products with water generating reactive oxygen species. Interaction of Hb with MTBE enhanced its aggregation rate and decreased lag time, indicating the antichaperone activity of MTBE upon interaction with Hb. Furthermore, the diabetic Hb showed more severe effects of MTBE, including heme degradation, reactive oxygen species production, unfolding, and antichaperone behavior than the nondiabetic Hb. The results from molecular docking suggested that the special interaction site of MTBE in the vicinity of Hb heme group is responsible for heme degradation.