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1.
The U.S. National Environmental Policy Act (NEPA) of 1969 heralded in an era of more robust attention to environmental impacts resulting from larger scale federal projects. The number of other countries that have adopted NEPA's framework is evidence of the appeal of this type of environmental legislation. Mandates to review environmental impacts, identify alternatives, and provide mitigation plans before commencement of the project are at the heart of NEPA. Such project reviews have resulted in the development of a vast number of reports and large volumes of project-specific data that potentially can be used to better understand the components and processes of the natural environment and provide guidance for improved and efficient environmental protection. However, the environmental assessment (EA) or the more robust and intensive environmental impact statement (EIS) that are required for most major projects more frequently than not are developed to satisfy the procedural aspects of the NEPA legislation while they fail to provide the needed guidance for improved decision-making. While NEPA legislation recommends monitoring of project activities, this activity is not mandated, and in those situations where it has been incorporated, the monitoring showed that the EIS was inaccurate in direction and/or magnitude of the impact. Many reviews of NEPA have suggested that monitoring all project phases, from the design through the decommissioning, should be incorporated. Information gathered though a well-developed monitoring program can be managed in databases and benefit not only the specific project but would provide guidance how to better design and implement future activities designed to protect and enhance the natural environment.  相似文献   

2.
Hydrologic disturbance reduces biological integrity in urban streams   总被引:1,自引:0,他引:1  
The impact of urbanization on stream ecosystems is linked by land cover changes to the alteration of the natural hydrology and subsequent physical disruption of stream biota and habitat. Seasonal floods are part of the natural disturbance regime of many streams, but urbanization increases their frequency and magnitude. This study evaluated the impact of hydrologic disturbance on fish and aquatic macroinvertebrates in 81 (56 urban/25 reference) Ohio streams. Hydrologic variables included annual and monthly 24-h rainfall maxima and computed annual peak discharge, with computation supported by GIS-based drainage area delineation and land cover characterization. Ohio biological criteria for fish and macroinvertebrates measured during the late spring and summer were negatively impacted by annual peak discharge in urban streams as compared to reference streams. Results support the application of stormwater best management practices as part of stream restoration efforts to mitigate urbanization impacts to fish and macroinvertebrates.  相似文献   

3.
The Chesapeake Bay benthic index of biotic integrity (B-IBI) was developed to assess benthic community health and environmental quality in Chesapeake Bay. The B-IBI provides Chesapeake Bay monitoring programs with a uniform tool with which to characterize bay-wide benthic community condition and assess the health of the Bay. A probability-based design permits unbiased annual estimates of areal degradation within the Chesapeake Bay and its tributaries with quantifiable precision. However, of greatest interest to managers is the identification of problem areas most in need of restoration. Here we apply the B-IBI to benthic data collected in the Bay since 1994 to assess benthic community degradation by Chesapeake Bay Program segment and water depth. We used a new B-IBI classification system that improves the reliability of the estimates of degradation. Estimates were produced for 67 Chesapeake Bay Program segments. Greatest degradation was found in areas that are known to experience hypoxia or show toxic contamination, such as the mesohaline portion of the Potomac River, the Patapsco River, and the Maryland mainstem. Logistic regression models revealed increased probability of degraded benthos with depth for the lower Potomac River, Patapsco River, Nanticoke River, lower York River, and the Maryland mainstem. Our assessment of degradation by segment and water depth provided greater resolution of relative condition than previously available, and helped define the extent of degradation in Chesapeake Bay.  相似文献   

4.
One hundred workers carried personal air sampling equipment during three days to assess exposure to inhalable and respirable Mn. A novel four-step chemical fractionation procedure developed for the speciation of Mn in workroom aerosols was applied for selected aerosol filters. Blood and urine samples were analysed for Mn. The geometric mean (GM) concentrations of inhalable (n = 265) and respirable (n = 167) Mn determined in all filters were 254 microg m(-3) and 28 microg m(-3) respectively. Only 10.6% (95% CI 8.9-12.5) respirable Mn was found in the inhalable fraction when inhalable and respirable samples collected in parallel were considered (n = 153 pairs). There was a high correlation (Pearson's r = 0.70; p < 0.001) between respirable and inhalable Mn. The largest amounts of Mn in the inhalable aerosol fraction were found as Mn0 and Mn2+ (47.4%), whereas 28% was practically "insoluble". The associations between B-Mn and aerosol concentrations of Mn were weak, but an association was found between U-Mn and respirable Mn; Pearson's r being 0.38 between "soluble" respirable Mn and U-Mn. No significant association was found between the "insoluble" components (probably SiMn) and Mn in biological samples.  相似文献   

5.
6.
The Minnesota River Basin (MRB), situated in the prairie pothole region of the Upper Midwest, contributes excessive sediment and nutrient loads to the Upper Mississippi River. Over 330 stream channels in the MRB are listed as impaired by the Minnesota Pollution Control Agency, with turbidity levels exceeding water quality standards in much of the basin. Addressing turbidity impairment requires an understanding of pollutant sources that drive turbidity, which was the focus of this study. Suspended volatile solids (SVS), total suspended solids (TSS), and turbidity were measured over two sampling seasons at ten monitoring stations in Elm Creek, a turbidity impaired tributary in the MRB. Turbidity levels exceeded the Minnesota standard of 25 nephelometric units in 73% of Elm Creek samples. Turbidity and TSS were correlated (r 2?=?0.76), yet they varied with discharge and season. High levels of turbidity occurred during periods of high stream flow (May–June) because of excessive suspended inorganic sediment from watershed runoff, stream bank, and channel contributions. Both turbidity and TSS increased exponentially downstream with increasing stream power, bank height, and bluff erosion. However, organic matter discharged from wetlands and eutrophic lakes elevated SVS levels and stream turbidity in late summer when flows were low. SVS concentrations reached maxima at lake outlets (50 mg/l) in August. Relying on turbidity measurements alone fails to identify the cause of water quality impairment whether from suspended inorganic sediment or organic matter. Therefore, developing mitigation measures requires monitoring of both TSS and SVS from upstream to downstream reaches.  相似文献   

7.
8.
The effect of altitude and water temperature on biomonitoring of freshwater quality was examined along an unpolluted area (36 km in length) of the upper Río Tajo (central Spain). The macrobenthic and fish communities were studied, and the Biological Monitoring Water Quality (BMWQ) method was applied. As expected, values of altitude and temperature respectively decreased and increased with increasing distance from the river source; these two physical parameters exhibited a negative and significant (P<0.05) correlation coefficient between them. However, despite evident changes in the functional structure of both aquatic communities along the study area, BMWQ scores were similar at all sampling sites. Pearson correlation coefficients between physical and biological parameters were not significant (P>0.05). The BMWQ index only exhibited significant (positive) correlation coefficients with macrobenthic and fish biomasses, indicating that freshwater quality could affect the biological production of fluvial ecosystems. It is concluded that biomonitoring of freshwater quality may be independent of the influence of altitude and water temperature at local spatial scales. Nonetheless, further investigations would be needed to clearly differentiate between the effects of anthropogenic and natural causes on biological monitoring at larger spatial scales.  相似文献   

9.
10.
Environmental agencies across the United States have searched for adequate methods to assess anthropogenic impacts on the environment. Biological assessments, which compare the taxonomic composition of an aquatic assemblage to relevant biocriteria, have surfaced as an effective method to assess the ecological integrity of US waterbodies. In this study, bioassessment data were collected and analyzed in conjunction with physical habitat and chemical stressor data for streams and rivers within the San Diego basin from 1998 through 2005. Physical stressors such as sediment loading, riparian destruction, and in-stream habitat homogenization affect many locations in the region. However, physical habitat measures alone were found to frequently overestimate the biological integrity of streams in the region. Many sites within the San Diego Basin, although unaffected by physical stressors, continue to exhibit low biological integrity scores. Sites with low biological integrity tend to possess higher specific conductance and salinity compared to sites with high biological integrity. We suggest that one possible reason for these differences is the source water used for municipal purposes.  相似文献   

11.
Considerable resources are being used to develop and implement bioassessment methods for wetlands to ensure that “biological integrity” is maintained under the United States Clean Water Act. Previous research has demonstrated that avian composition is susceptible to human impairments at multiple spatial scales. Using a site-specific disturbance gradient, we built avian wetland indices of biological integrity (AW-IBI) specific to two wetland classification schemes, one based on vegetative structure and the other based on the wetland’s position in the landscape and sources of water. The resulting class-specific AW-IBI was comprised of one to four metrics that varied in their sensitivity to the disturbance gradient. Some of these metrics were specific to only one of the classification schemes, whereas others could discriminate varying levels of disturbance regardless of classification scheme. Overall, all of the derived biological indices specific to the vegetative structure-based classes of wetlands had a significant relation with the disturbance gradient; however, the biological index derived for floodplain wetlands exhibited a more consistent response to a local disturbance gradient. We suspect that the consistency of this response is due to the inherent nature of the connectivity of available habitat in floodplain wetlands.  相似文献   

12.
This study was conducted to evaluate the usefulness of various biological parameters for monitoring of workers exposed to methyl ethyl ketone (MEK). Fifty male workers from a large magnetic videotape factory participated in this study. Personal air samples were collected using 3M organic vapor monitors and analysed for MEK by gas chromatography with flame ionisation detector (FID). 10 mL of urine; blood (1 mL) and exhaled air were also collected at the end of an 8-hour workshift. The headspace GC method was applied for measurement of urinary and blood MEK. MEK in expired air was analysed directly by using a GC/FID.The correlation coefficients (r) between environmental MEK and all other biological parameters measured show significant positive relationships. The r for environmental MEK and urine MEK was 0.84; for blood 0.73 and for breath 0.64. The correlation coefficients between blood and urine was 0.72; blood and breath was 0.88 and urine and breath 0.60. These findings suggest that measurements of unmetabolised MEK in blood, exhaled air and urine can be used for biological monitoring of MEK exposure. Nevertheless, laboratory methodological assessment is in favour of measuring urinary MEK as it is non-invasive and does not have to be analysed immediately after collection.  相似文献   

13.
14.
The more than 10 years concern for lead in the European Community from the environmental and workplace point fo view, have lead to the adoption of a number of Directives limiting human exposure to head.Furthermore a Directive on the Biological screening of the population for lead was adopted in 1977 to obtain an overall assessment of the exposure to lead of the general population. The results of this assessment are presented.  相似文献   

15.
The Oslo and Paris Commission (OSPAR) Guidelines for monitoring the biological effects of tributyltin compounds (TBT) were evaluated using data collected for preparation of a Celtic Seas Quality Status Report. Two types of survey were undertaken: broad scale, to determine wide impacts in coastal waters; and localised, around representative harbours to establish ranges of effect from recognised input points. This evaluation indicates that results from the broad scale surveys can be used to compare different areas of coastline. Nucella is widespread away from point sources although many individuals show some degree of imposex. Populations are generally not at risk. The localised surveys indicate that, in certain situations, the monitoring objectives can be met in the OSPAR Guidelines (subject to minor amendment). Criteria are identified for the selection of point sources suitable for monitoring under OSPAR Guidelines.  相似文献   

16.
Bioassessment methods for wetlands, and other bodies of water, have been developed worldwide to measure and quantify changes in “biological integrity.” These assessments are based on a classification system, meant to ensure appropriate comparisons between wetland types. Using a local site-specific disturbance gradient, we built vegetation indices of biological integrity (Veg-IBIs) based on two commonly used wetland classification systems in the USA: One based on vegetative structure and the other based on a wetland’s position in a landscape and sources of water. The resulting class-specific Veg-IBIs were comprised of 1–5 metrics that varied in their sensitivity to the disturbance gradient (R 2?=?0.14???0.65). Moreover, the sensitivity to the disturbance gradient increased as metrics from each of the two classification schemes were combined (added). Using this information to monitor natural and created wetlands will help natural resource managers track changes in biological integrity of wetlands in response to anthropogenic disturbance and allows the use of vegetative communities to set ecological performance standards for mitigation banks.  相似文献   

17.
In a cross-sectional study, 96 welders were compared with 96 control subjects. Also 27 former welders, all diagnosed as having manganism, were examined. Exposure to welding fumes was determined in the 96 welders, while the concentration of elements in whole blood and urine was determined in all subjects. The geometric mean (GM) concentrations of manganese (Mn) and iron in the workroom air were 97 microg m(-3) (range 3-4620 microg m(-3); n=188) and 894 microg m(-3) (range 106-20 300 microg m(-3); n=188), respectively. Thus the Mn concentration in the workroom air was on average 10.6% (GM) of that of the Fe concentration. No substantial difference was observed in the air Mn concentrations when welding mild steel as compared to welding stainless steel. The arithmetic mean (AM) concentration of Mn in whole blood (B-Mn) was about 25% higher in the welders compared to the controls (8.6 vs. 6.9 microg l(-1); p < 0.001), while the difference in the urinary Mn concentrations did not attain statistical significance. A Pearson's correlation coefficient of 0.31 (p < 0.01) was calculated between B-Mn and Mn in the workroom air that was collected the day before blood sampling. Although the exposure to welding fumes in the patients had ceased on average 5.8 years prior to the study (range 4 years-7 years), their AM B-Mn concentration was still higher than in referents of similar age (8.7 microg l(-1) vs. 7.0 microg l(-1)). However, their urinary concentrations of cobolt, iron and Mn were all statistically significantly lower.  相似文献   

18.
The implementation of effective strategies to mitigate the impacts of urbanization on waterways represents a major global challenge. Monitoring data plays an important role in the formulation of these strategies. Using monitoring and historical data compiled from around an urban area (Baltimore, USA), this paper is an assessment of the potential and limitations of the use of fish assemblage monitoring data in watershed restoration. A discriminant analysis between assemblages from urban and reference sites was used to determine faunal components which have been reduced or eliminated from Baltimore area waterways. This analysis produced a strong discrimination between fish assemblages from urban and reference sites. Species primarily associated with reference sites varied taxonomically and ecologically, were generally classified as pollution intolerant, and were native. Species associated with urbanized sites were also native, varied taxonomically and ecologically, and were mixed in pollution tolerance. One factor linking most species associated with reference sites was spawning mode (lithophilic). Spawning habitat limitations may be the mechanism through which these species have been reduced in the urbanized faunas. While this presents a strong general hypothesis, information regarding the specific habitat requirements and responses to urbanization of these species is limited. This represents a limitation to producing effective restoration strategies based on exact goals and targets. Without these, determining the type and number of restoration activities required to restore ecological communities remains problematic.  相似文献   

19.
To evaluate exposure to benzene in urban and rural areas, an investigation into personal exposure to benzene in traffic policemen, police drivers and rural (roadmen) male outdoor workers was carried out. Personal samples and data acquired using fixed monitoring stations located in different areas of the city were used to measure personal exposure to benzene in 62 non-smoker traffic policemen, 22 police drivers and 57 roadmen. Blood benzene, urinary trans-trans muconic acid (t,t-MA) and S-phenyl-mercapturic acid (S-PMA) were measured at the end of work shift in 62 non-smoker traffic policemen, 22 police drivers and 57 roadmen and 34 smoker traffic policemen, 21 police drivers and 53 roadmen. Exposure to benzene was similar among non-smoker traffic policemen and police drivers and higher among non-smoker urban workers compared to rural workers. Blood benzene, t,t-MA and S-PMA were similar among non-smoker traffic policemen and police drivers; blood benzene and t,t-MA were significantly higher in non-smoker urban workers compared to rural workers. Significant increases in t,t-MA were found in smokers vs. non-smokers. In non-smoker urban workers airborne benzene and blood benzene, and t,t-MA and S-PMA were significantly correlated. This study gives an evaluation of the exposure to benzene in an urban area, comparing people working in the street or in cars, to people working in a rural area. Benzene is a certain carcinogen for humans. The results we showed should lead to more in-depth studies about the effects on health of these categories of workers.  相似文献   

20.
Offshore geologic storage of carbon dioxide (CO2), known as offshore carbon capture and sequestration (CCS), has been under active investigation as a safe, effective mitigation option for reducing CO2 levels from anthropogenic fossil fuel burning and climate change. Along with increasing trends in implementation plans and related logistics on offshore CCS, thorough risk assessment (i.e. environmental impact monitoring) needs to be conducted to evaluate potential risks, such as CO2 gas leakage at injection sites. Gas leaks from offshore CCS may affect the physiology of marine organisms and disrupt certain ecosystem functions, thereby posing an environmental risk. Here, we synthesize current knowledge on environmental impact monitoring of offshore CCS with an emphasis on biological aspects and provide suggestions for better practice. Based on our critical review of preexisting literatures, this paper: 1) discusses key variables sensitive to or indicative of gas leakage by summarizing physico-chemical and ecological variables measured from previous monitoring cruises on offshore CCS; 2) lists ecosystem and organism responses to a similar environmental condition to CO2 leakage and associated impacts, such as ocean acidification and hypercapnia, to predict how they serve as responsive indicators of short- and long-term gas exposure, and 3) discusses the designs of the artificial gas release experiments in fields and the best model simulation to produce realistic leakage scenarios in marine ecosystems. Based on our analysis, we suggest that proper incorporation of biological aspects will provide successful and robust long-term monitoring strategies with earlier detection of gas leakage, thus reducing the risks associated with offshore CCS.  相似文献   

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