Appreciable amounts of selenium in spring and well waters can be found due to geological occurrence. Concentrations of as much as 400 9000 μg/l have been reported in U. S. waters.These levels are 8 to 180 times the c...Appreciable amounts of selenium in spring and well waters can be found due to geological occurrence. Concentrations of as much as 400 9000 μg/l have been reported in U. S. waters.These levels are 8 to 180 times the current EPA drinking water standard and approximate dietary exposures of 4900μg in selenosis regions of China. Reviews of health significance of the elevated drinking water exposures to U. S. populations revealed elevated concentrations of selenium in urine and blood. A decrease in glutathione peroxidase activity in such instances was noted. However noticeable symptoms and signs seem absent in studies reviewed. A comparison of intake levels (diet or drinking water) to urinary excretion for residents of China and the U. S. produced a correlation coefficient, r = 0. 82 (P < 0. 01 ) for the three research studies available展开更多
In recent years, many serious forest fires occurred in precious Pinus pumila forests in Daxing'anling Mountains of Heilongjiang Province and Inner Mongolia. But up to now, there is still a lack of proper understan...In recent years, many serious forest fires occurred in precious Pinus pumila forests in Daxing'anling Mountains of Heilongjiang Province and Inner Mongolia. But up to now, there is still a lack of proper understanding of fire occurrence environments in P. pumila forests. In present paper, we investigated and studied the fire occurrence environments. The results showed that fires in P. pumila forests had their own special fire environments. Abundant fuel, drought weather, dry thunder and high altitude terrain created the special fire occurrence environments in P. pumila forests in Daxing'anling展开更多
Sea Nine 211, with 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one（DCOIT） being the biocidal ingredient, is a widely-used antifouling agent to deter the undesirable biofouling phenomenon. It is commercially promoted as ...Sea Nine 211, with 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one（DCOIT） being the biocidal ingredient, is a widely-used antifouling agent to deter the undesirable biofouling phenomenon. It is commercially promoted as an environmentally acceptable antifoulant mainly due to its claimed rapid degradation in marine environment. However, increasing researches document varying degradative kinetics in different environments, proving that Sea Nine 211 is actually not degraded equally fast around the world（half-life between〈 1 day and 13.1 days）. Large-scale application of Sea Nine 211 in antifouling coatings has also caused global contamination of marine environment in various compartments. For example, accumulation of Sea Nine 211 is detected as high as 3700 ng/L in Spanish seawater and 281 ng/g dry weight in Korean sediment. Considering that Sea Nine 211 is highly toxic against non-target marine organisms, environmental risk assessment finds that most marine organisms are endangered by Sea Nine 211 in worst-case scenario. Its endocrine disrupting and reproductive impairing effects at environmentally worst-case concentrations further constitute a long-term threat to the maintenance of population stability.Therefore, in the light of the varying degradability, environmental pollution and high toxicity, especially the endocrine disruption, Sea Nine 211 as an antifouling agent is likely to cause non-negligible damages to the marine ecosystem. There is an urgency to perform a systematic ecological risk assessment of Sea Nine 211 to prevent the potential impacts on the health of marine environment. A regular monitoring also becomes necessary to place the usage of antifouling biocides under control.展开更多
文摘Appreciable amounts of selenium in spring and well waters can be found due to geological occurrence. Concentrations of as much as 400 9000 μg/l have been reported in U. S. waters.These levels are 8 to 180 times the current EPA drinking water standard and approximate dietary exposures of 4900μg in selenosis regions of China. Reviews of health significance of the elevated drinking water exposures to U. S. populations revealed elevated concentrations of selenium in urine and blood. A decrease in glutathione peroxidase activity in such instances was noted. However noticeable symptoms and signs seem absent in studies reviewed. A comparison of intake levels (diet or drinking water) to urinary excretion for residents of China and the U. S. produced a correlation coefficient, r = 0. 82 (P < 0. 01 ) for the three research studies available
基金supported by the Central Public-interest Scientific Institution Basal Research Fund Supporting Program(CAFRIFEEP200809)the State Forestry Administration Key Project (2006-84)
文摘In recent years, many serious forest fires occurred in precious Pinus pumila forests in Daxing'anling Mountains of Heilongjiang Province and Inner Mongolia. But up to now, there is still a lack of proper understanding of fire occurrence environments in P. pumila forests. In present paper, we investigated and studied the fire occurrence environments. The results showed that fires in P. pumila forests had their own special fire environments. Abundant fuel, drought weather, dry thunder and high altitude terrain created the special fire occurrence environments in P. pumila forests in Daxing'anling
文摘Sea Nine 211, with 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one（DCOIT） being the biocidal ingredient, is a widely-used antifouling agent to deter the undesirable biofouling phenomenon. It is commercially promoted as an environmentally acceptable antifoulant mainly due to its claimed rapid degradation in marine environment. However, increasing researches document varying degradative kinetics in different environments, proving that Sea Nine 211 is actually not degraded equally fast around the world（half-life between〈 1 day and 13.1 days）. Large-scale application of Sea Nine 211 in antifouling coatings has also caused global contamination of marine environment in various compartments. For example, accumulation of Sea Nine 211 is detected as high as 3700 ng/L in Spanish seawater and 281 ng/g dry weight in Korean sediment. Considering that Sea Nine 211 is highly toxic against non-target marine organisms, environmental risk assessment finds that most marine organisms are endangered by Sea Nine 211 in worst-case scenario. Its endocrine disrupting and reproductive impairing effects at environmentally worst-case concentrations further constitute a long-term threat to the maintenance of population stability.Therefore, in the light of the varying degradability, environmental pollution and high toxicity, especially the endocrine disruption, Sea Nine 211 as an antifouling agent is likely to cause non-negligible damages to the marine ecosystem. There is an urgency to perform a systematic ecological risk assessment of Sea Nine 211 to prevent the potential impacts on the health of marine environment. A regular monitoring also becomes necessary to place the usage of antifouling biocides under control.
