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991.
Voss KA Pohlman A Viswanathan S Gibson D Purohit J 《Environmental monitoring and assessment》2012,184(3):1603-1616
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
992.
Spatial and seasonal distribution of nitrogen in marsh soils of a typical floodplain wetland in Northeast China 总被引:3,自引:0,他引:3
Bai J Wang Q Deng W Gao H Tao W Xiao R 《Environmental monitoring and assessment》2012,184(3):1253-1263
Horizontal and profile distributions of nitrogen in marsh soils in different seasons were studied in a typical site within
the Erbaifangzi wetland in Northeast China. Results showed that there was higher spatial heterogeneity for nitrate nitrogen
(NO3--_{3}^{-}-N) and ammonium nitrogen (NH4+_{4}^{+}–N), as well as available nitrogen (AN), in surface soils in July compared to that in September. Relative to July, the mean
nitrogen contents in surface soils were slightly higher in September; however, in November, soils contained significantly
lower NO3--_{3}^{-}-N and NH4+_{4}^{+}–N, higher AN, organic nitrogen (Org-N), and total nitrogen (TN). Except for mineral nitrogen, no significant differences
were observed between Org-N and TN contents in September and November. Nitrogen contents generally declined exponentially
with depth along soil profiles in three sampling dates (July, September, and November), except for a significant accumulation
peak of NO3--_{3}^{-}-N at the 20–30 cm depth in September. However, NH4+_{4}^{+}–N contents showed a vertical alternation of “increasing and decreasing” in both July and September, while nearly kept constant
with depth in November. The depth ranking of nitrogen showed the shallowest distribution for AN, followed by Org-N and TN,
while deeper distributions for NO3--_{3}^{-}-N and NH4+_{4}^{+}–N. TN, Org-N, and AN were significantly correlated with soil organic matter and total phosphorus. Soil pH values were significantly
correlated with TN and AN contents in surface soils. Clay contents showed significant correlations with nitrogen contents
except for NO3--_{3}^{-}-N in surface soils and NH4+_{4}^{+}–N in profile soils. However, soil moisture was not significantly correlated with nitrogen contents among all soil samples. 相似文献
993.
The Po valley in northern Italy is renowned for its high air pollutant concentrations. Measurements of air pollutants from a background site in Modena, a town of 200 thousand inhabitants within the Po valley, are analysed. These comprise hourly data for CO, NO, NO(2), NO(x), and O(3), and daily gravimetric equivalent data for PM(10) from 1998-2010. The data are analysed in terms of long-term trends, annual, weekly and diurnal cycles, and auto-correlation and cross-correlation functions. CO, NO and NO(2) exhibit a strongly traffic-related pattern, with daily peaks at morning and evening rush hour and lower concentrations over the weekend. Ozone shows an annual cycle with a peak in July due to local production; notwithstanding the diurnal cycle dominated by titration by nitrogen oxide, the decreasing long term trend in NO concentration did not affect the long term trend in O(3), whose mean concentration remained steady over the sampling period. PM(10) shows a strong seasonality with higher concentration in winter and lower concentration in summer and spring. Both PM(10) and ozone show a marked weekly cycle in summer and winter respectively. Regressions of PM(10) upon NO(x) show a consistently greater intercept in winter, representing higher secondary PM(10) in the cooler months of the year. There is a seasonal pattern in primary PM(10) to NO(x) ratios, with lower values in winter and higher values in summer, but the reasons are unclear. 相似文献
994.
Monavari SM Omrani GA Karbassi A Raof FF 《Environmental monitoring and assessment》2012,184(4):1841-1846
Environment problems associated with the generation of waste are part of societal changes where households play an important
role. These societal changes influence the size, structure and characteristic of given households. For the effective planning
of solid-waste handling infrastructure, it is essential to know the quantity of waste generation and its composition. This
paper presents the findings of a study carried out in an urban municipal area in Iran to determine the household solid-waste
generation rate and waste composition based on field surveys and to determine the related socioeconomic parameters. The dependent
variables were waste generation and composition, and independent variables were family size, family employment, age, number
of room and education. Over 400 sample households were selected for the study using a stratified random sampling methodology
and from five different socioeconomic groups. Waste collected from all groups of households were segregated and weighted.
Waste generation rate was 5.4 kg/household/day. Household solid waste comprised of ten categories of wastes and with the largest
component (76.9%). The generation and composition of household solid waste were correlated with family size, education level
and households income. This paper adequately suggests new insights concerning the role of socioeconomic parameters in affecting
the generation of household waste. 相似文献
995.
The total petroleum hydrocarbons (TPH) pollution in regional agricultural soils was investigated. Seventy soil samples collected
from surface layers (0–20 cm) and horizons of five selected pedons in the vicinity of a petrochemical complex in Guangzhou,
China were analyzed, and the vertical variation and spatial variability of TPH were evaluated. The TPH concentration in top
soils around the petrochemical complex ranged from 1,179.3 to 6,354.9 mg kg − 1, with the average of 2,676.6 mg kg − 1. Furthermore, significant differences between land-use types showed that the TPH concentration in top soils was strongly
influenced by accidental spills. Both the TPH trends in pedons and the identified hot-spot areas also showed that the accidental
explosions or burning accidents were mainly responsible for the pollution. The results reported here suggest that the regular
monitoring and inspection shall be conducted for safety and to avoid or minimize the accidents, and the effective measures
should be taken to remediate the contaminated areas and to assure that the important industrialization of Guangzhou area would
not mean human health risks near the petrochemical complex. 相似文献
996.
Karadag A 《Environmental monitoring and assessment》2012,184(3):1617-1632
This paper is a summary of a project changed into a book named by “Changing Environment, City and Identity in Soma with the
Geographical Evaluations” issued on May 2005. In this research, Soma, which is one of the most remarkable districts in Manisa
in the West Anatolia from the point of economical figures, is assessed with its physical environment potential, improving
economical activities and changing socio-economical structure. Owing to the open coal basins in the northeast and southwest
of the district where lignite is produced and the impact of the thermic power plant near the city centre, Soma has changed
on a large scale. This change has introduced some environmental problems into the district such as the devastation of the
forestry land; the infertility of farming land; and soil, water and air pollution. Even though the change under discussion
has led to many problems to deal with, it has also influenced its socio-economical structure to a large extent and revealed
new type of inhabitants having different life expectations and aims. In conclusion, in this article, changing environment
and city structure after lignite processing and thermic station establishment in Soma are discussed through the effective
geographical factors. The new city profile formed by the local dynamics in question is evaluated according to the data obtained
by the studies made in the neighbourhood. 相似文献
997.
Concentration of heavy metals (Cd, Ni, Zn, Fe, Cu, Mn, Pb, Cr, Hg and As) in the waters of River Yamuna and in the soil of
agricultural fields along its course in Delhi are reported from 13 sites, spread through the Delhi stretch of Yamuna, starting
from the Wazirabad barrage till the Okhla barrage. Varying concentration of heavy metals was found. Peaks were observed in
samples collected downstream of Wazirabad and Okhla barrage, indicating the anthropogenic nature of the contamination. The
Wazirabad section of the river receives wastewater from Najafgarh and its supplementary drains, whereas the Shahdara drain
releases its pollution load upstream of the Okhla barrage. Average heavy metal concentration at different locations in the
river water varied in the order of Fe>Cr>Mn>Zn>Pb>Cu>Ni>Hg>As>Cd. The river basin soil shows higher level of contamination
with lesser variation than the water samples among sampling locations, thereby suggesting deposition over long periods of
time through the processes of adsorption and absorption. The average heavy metal concentration at different locations in soil
varied in the order of Fe>Mn>Zn>Cr>Pb>Ni>Hg>Cu>As>Cd. 相似文献
998.
The analysis of heavy metals is very important for assessing the feasibility of the agricultural utilization for the municipal
sludge. In this paper, a four-step sequential extraction method was applied to extract heavy metals (Cu, Zn, Mn, Cr, and Ni)
in municipal sludges from seven individual wastewater treatment plants located in Jilin and Heilongjiang Province, China,
for estimating the mobility and bioavailability of the metal ions in the agricultural application. The total concentrations
of heavy metals and their chemical fractions after the sequential extraction were determined. Principal component analysis
(PCA) was applied to analyze the relations of heavy metals fractions in the municipal sludges. Experimental results indicated
that the total concentrations of Cu, Zn, Cr, and Ni in all sludge samples were below the threshold values set out by the Chinese
legislation (GB18918-2002). Specially, Zn had a high bioavailability and mobility, Cu and Cr had potential bioavailability,
while Mn mainly existed in the residual fraction of municipal sludge. On the other hand, Ni had different mobility in different
municipal sludge. PCA results were confirmed by the environmental behavior of heavy metals. 相似文献
999.
Warren C Duzgoren-Aydin NS Weston J Willett KL 《Environmental monitoring and assessment》2012,184(2):1107-1119
Hurricanes are relatively frequent ecological disturbances that may cause potentially long-term impacts to the coastal environment.
Hurricane Katrina hit the Mississippi Gulf Coast in August 2005, and caused a storm surge with the potential to change the
trace element content of coastal surface sediments. In this study, surface estuarine and marine sediments were collected monthly
following the storm from ten sites along the Mississippi Gulf Coast (Mobile Bay, Grand Bay Bayous Heron and Cumbest, Pascagoula,
Ocean Springs, Biloxi Gulf, Back Biloxi Bay, Gulfport Gulf, Gulfport Courthouse Rd, and Gulfport Marina). Concentrations of
V, Cr, Mn, Fe, Co, Ni, Zn, As, Cd, and Pb were measured by inductively coupled plasma–mass spectrometry to evaluate their
temporal and spatial variations in the year following Hurricane Katrina. Sediments were characterized by pH, particle size
distribution and total carbon and nitrogen content. Trace element contents of the sediments were determined in both <2 mm
and <63 μm grain size fractions. Results revealed no significant temporal and spatial variability in trace element concentrations,
in either size fraction. Potential ecological risk of the sediments was assessed by using NOAA SQuiRTs’ guideline values;
most concentrations remained below probable adverse effects guidelines to marine organisms suggesting that trace elements
redistributed by Hurricane Katrina would not cause an adverse impact on resident organisms. Instead, the concentrations of
trace elements were site-dependent, with specific contaminants relating to the use of the area prior to Hurricane Katrina. 相似文献
1000.
Karakaya and Sultansuyu Dam Lakes, located in the eastern part of Turkey, are important water sources, both for irrigation
and fishery. The main goal of the study was to investigate water qualities of dam lakes using a set of biomarkers in the fish
Cyprinus carpio. For this aim, field sample and laboratory-acclimated fish were compared to identify changes in selected biomarkers. The
activities of ethoxyresorufin-O-deethylase, glutathione S-transferase, glutathione reductase, and carboxylesterase were determined in liver samples. Also, plasma and liver lactate
dehydrogenase, aspartate aminotransferase, and alanine aminotransferase activities were assayed. Brain acetylcholinesterase
and carboxylesterase activities were also determined. The hepatosomatic index and condition factors were calculated. Plasma
vitellogenin assays were evaluated for the presence of xenoestrogen. Physicochemical values of water samples showed the existence
of eutrophication risk, and also, some chemicals in both lakes were determined to be over tolerable limits. The comparisons
of samples from both dam lake and laboratory-acclimated fish showed that the lakes may be at risk of pollution by some xenobiotics,
namely xenoestrogens and acetylcholinesterase-inhibiting agents. 相似文献