共查询到20条相似文献,搜索用时 15 毫秒
1.
Osborn LV Kurek JT Kriech AJ Fehsenfeld FM 《Journal of environmental monitoring : JEM》2001,3(2):185-190
A subset of polycyclic aromatic compounds (PACs), which contain 4-6 annulated rings, has been documented as the source of carcinogenicity in animal skin painting studies of petroleum products and asphalt fumes (M. L. Machado, P. W. Beatty, J. C. Fetzer, A. H. Glickman and E. L. McGinnis, Fundam. Appl. Toxicol., 1993, 21, 492; T. A. Roy, S. W. Johnson, G. R. Blackburn and C. R. Mackerer, Fundam. Appl. Toxicol., 1988, 10, 466). Because of the chemical complexity of these materials, it has been difficult to identify the specific compounds within this broad range of PACs responsible for their carcinogenicity. An alternative approach using luminescence spectroscopy was taken in this study to quantify, without identification, a subset of these compounds that appears to cause cancer. The fluorescence response at a specific wavelength pair was obtained for 39 laboratory asphalt fume condensates from animal skin painting studies, yielding a linear correlation coefficient of R2 = 0.96 between the fluorescence response in these materials and the carcinogenicity found in animal studies. In the absence of other asphalt fume condensates from animal studies, 17 petroleum oils were also evaluated using this method and compared with the available animal skin painting data. The details of the method include a clean-up step that removes the highly polar compounds and spectral subtraction of two- and three-ring PAC interference, both of which add to the fluorescence response, yet were not found to contribute to a carcinogenic response from skin painting studies. Full scan fluorescence plots also produce a fingerprint which can be used to assess contamination, such as coal tar products or mixtures of materials, that are not defined as asphalt, yet may be present in the working environment. 相似文献
2.
MM5-SMOKE-CMAQ as a modeling tool for 8-h ozone regulatory enforcement: application to the state of Arizona 总被引:1,自引:0,他引:1
Sang-Mi Lee H. J. S. Fernando S. Grossman-Clarke 《Environmental Modeling and Assessment》2007,12(1):63-74
The Penn State/NCAR Mesoscale Meteorological Model 5 (MM5), Sparse Matrix Operator Kernal Emissions (SMOKE), and Community
Multiscale Air Quality (CMAQ) modeling systems were employed to simulate ozone concentration distribution within the State
of Arizona, in particular, Phoenix air basin, as supporting information to designate nonattainment areas of the U.S. Environmental
Protection Agency's new 8-h ozone standard. In general, based on statistical comparisons between predictions and available
(sparsely distributed) observations, the modeling system performed reasonably well for the Phoenix basin, thus proving it
to be a useful tool for both regulatory as well as research applications. Detailed inspection, however, revealed a serious
problem with respect to the details of the ozone distribution in that for some days the transition from downslope flow to
upslope flow in the Phoenix basin was delayed in the model, causing the ozone distribution to show an unrealistic high-ozone
bias toward the west valley. Implementation of a modified subgrid parameterization improved the time of transition, and hence
the prediction of ozone and its precursor distributions. This study points to possible inadequacies of commonly used subgrid
parameterizations in dealing with rapidly changing flow conditions such as morning (and evening) transitions. 相似文献
3.
Rute Vieira João Nuno Fernandes Ana Estela Barbosa 《Environmental monitoring and assessment》2013,185(9):7659-7673
Road runoff is a linear diffuse source of pollution, with very specific characteristics. This study intends to improve the understanding of road runoff impacts in water bodies in Portugal. The chosen case study is S. Domingos reservoir catchment. The study analyzed land uses, the presence of pollution sources, and gathered temporal water quality data and performed site measurements and sample collection. The water quality data for the reservoir was provided by the national water quality monitoring system from the Portuguese Water Institute. The parameters selected were TSS, COD, NO3 ?, Cl?, and Cu. The results obtained revealed that the presence of IP6 highway at S. Domingos catchment affects the water quality; however, the impacts are not significant due to the high dilution effect of the reservoir volume. Agriculture, the main land use of the catchment, is responsible for introducing pollutants such as TSS, Cl?, COD, N, and P in the local water streams and at the reservoir. TSS, COD, and Cu are pollutants generated by the road. The success of the study was very much dependent on the availability of 12 years of historic water quality data for S. Domingos reservoir, and the use of the moving average method. Taking into consideration the high variability of hydrological variables in Mediterranean climates, the concentration of pollutants in the water bodies must always be assessed in a significant time period. 相似文献
4.
5.
Richard Hunter Anderson Michael J. Kravitz 《Environmental monitoring and assessment》2010,167(1-4):631-641
Geochemical association plots are used as a screening tool for environmental site assessments and use empirical log–log relationships between total trace metal concentrations and concentrations of a major (i.e., reference) soil metal constituent, such as iron (Fe), to discern sites with naturally elevated trace metal levels from sites with anthropogenic contamination. Log–log relationships have been consistently observed between trace metal and reference metal concentrations and are often considered constant. Consequently, we used a regional geochemistry data set to evaluate background trace metal/Fe log–log associations across soils with highly diverse composition. Our results indicate that, although geochemical associations may be proportional, they significantly differ across predominant United States Department of Agriculture (USDA) soil orders. This suggests that highly complex interactions between soil-forming factors and variable secondary clay mineral composition affect the ratio of trace metals to Fe concentrations in soils. Also, intra-order variability in trace metal/Fe ratios generally ranged multiple orders of magnitude which suggest that the order level of the USDA soil taxonomic system is insufficient to reasonably classify background trace metal concentrations. Consequently, geochemical association plots are a useful screening tool for environmental site assessments, but ubiquitous application of generic background metal data sets could result in erroneous conclusions. Because significantly different ratios were observed across predominant USDA soil orders, an agglomerative clustering technique was used to elucidate hierarchical patterns of association. We present these results as a mechanism to aid environmental assessors in screening candidate background metal data sets for their applicability to site-specific soil composition; although site-specific background metal data should be utilized if ample pristine reference sites with similar (i.e., sub-order) soil composition can be identified and sampled. 相似文献
6.
R. S. C. Coimbra M. S. Mascarenhas V. B. Saraiva C. R. Santos R. M. Lopes R. A. Hauser-Davis V. P. S. Oliveira M. M. Molisani M. G. Almeida C. E. Rezende C. E. V. Carvalho M. M. Oliveira 《Environmental monitoring and assessment》2018,190(9):564
Tropical coastal lagoons are highly productive environments exhibiting high biodiversity. However, the use of these ecosystems by local communities is of concern, since this generally leads to environmental degradation. The Imboassica coastal lagoon, located in Macaé city, in Northern Rio de Janeiro, is an important ecosystem in the state, however, already displaying signs of anthropogenic impacts. Carnivorous fish Hoplias malabaricus specimens were sampled from this impacted site, as well as from a reference area. Fish from Imboassica Lagoon presented lower condition factor, lower cholinesterase activity, and higher percentage of erythrocyte micronuclei when compared to fish from the reference site. Metals in fish from Imboassica Lagoon were always higher than Encantada Lagoon, with some seasonal differences, where some metals were higher in the rainy season compared to the dry season in muscle tissue, with the exception of Cu, Fe, Sr, and Zn; and in the liver, except for Ba, Cd, Cr, Ni, and Sr. Cr and Mn in the edible muscle portion of the fish were higher than the limits established by Brazilian and International legislations as permissible for human consumption, thus leading to concerns regarding public health risks for the local population that use fish as their main protein source. 相似文献
7.
Prata C Ribeiro A Cunha  Gomes NC Almeida A 《Journal of environmental monitoring : JEM》2012,14(1):64-70
Some health important enteric viruses are considered to be emerging waterborne pathogens and so the improvement of detection of these viruses in the aquatic environment is one of the most important steps in dealing with these pathogens. Since these viruses may be present in low numbers in water, it is necessary to concentrate water samples before viral detection. Although there are several methods to concentrate viruses in environmental waters, all present some drawbacks and consequently the method should be chosen that, despite its limitations, is adequate to achieve the aim of each study. As the effectiveness of the concentration methods is evaluated by determining the efficiency of viral recovery after concentration, it is important to use a simple and effective approach to evaluate their recovery efficiency. In this work ultracentrifugation, usually used as a secondary step for virus concentration, was evaluated as the main method to concentrate directly viruses in environmental water samples, using the microscopic enumeration of virus-like particles (VLP) as a new approach to estimate the efficiency of recovery. As the flocculation method is currently employed to concentrate viruses in environmental waters, it was also used in this study to assess the efficiency of the ultracentrifugation as the main viral concentration method in environmental waters. The results of this study indicate that ultracentrifugation is an adequate approach to concentrate viruses directly from environmental waters (recovery percentages between 66 and 72% in wastewaters and between 66 and 76% in recreational waters) and that the determination of VLP by epifluorescence microscopy is a simple, fast and cheap alternative approach to determine the recovery efficiency of the viral concentration methods. 相似文献
8.
Harwell MC Surratt DD Barone DM Aumen NG 《Environmental monitoring and assessment》2008,147(1-3):445-462
Agricultural and urban runoff pumped into the perimeter canals of the Arthur R. Marshall Loxahatchee National Wildlife Refuge (Refuge), a 58,320-ha soft-water wetland, has elevated nutrients which impact the Refuge interior marsh. To best manage the Refuge, linkages between inflows to the perimeter canals and environmental conditions within the marsh need to be understood. Conductivity, which typically is high in the canals and lowest at the most interior sites, was used as a surrogate tracer to characterize patterns of constituent transport. The Refuge was initially classified into four zones based upon patterns and variability in conductivity data: Canal Zone; Perimeter Zone (canal to 2.5 km into the interior); Transition Zone (2.5 to 4.5 km from the canal); Interior Zone (>4.5 km from the canal). Conductivity variability declined from the Perimeter to the Interior Zone, with the highest variability in the marsh observed in the Perimeter Zone and the lowest variability observed in the Interior Zone. Analysis of other water quality parameters indicated that conditions in the Perimeter and Transition Zones were different, and more impacted, than in the Interior Zone. In general, there was a positive relationship between structure inflows and canal phosphorus concentrations, including discharges from treatment wetlands and bypasses of untreated water. This classification approach is applicable for stratified sampling designs, resolving spatial bias in water quality models, and in aiding in management decisions about resource allocation. 相似文献
9.
O. Igwe O. V. Omonona O. S. Onwuka O. D. Nnebedum 《Environmental monitoring and assessment》2014,186(12):8063-8080
This study investigated the impacts of asbestos wastes on soils in Emene-Enugu, southeastern Nigeria, generated by the activities of a major asbestos products manufacturing company in southeastern Nigeria. The methods of investigation included vertical electrical sounding (VES), 2-D horizontal resistivity profiling (HRP), induced polarization (IP) survey, chemical analysis of plant tissues and standard penetration tests of soil samples. The 2-D HRP and IP identified six closed waste pits alongside the two active pits. The VES revealed four geoelectrical layers in the area: from bottom to top; the inferred lithologies included dark shale, clay, gravel and recent sands. The geochemical data results revealed that Cd concentration of the soils of the waste pits is above the contaminated land exposure assessment soil guideline value for residential and allotment land uses. The geochemical pollution indices classified the soils as “unpolluted” to “extremely polluted”. Bioconcentration factor of Pb in plant tissues was found to be above recommended limits of 0.045. The geotechnical parameters indices revealed that the soils varied from “very soft” to “stiff” and “very loose” to “medium”. Soils of the active pits have very low strength and bearing capacity while closed pits have high strength and bearing capacity. It may be safe, therefore, to conclude that as the wastes are completely turned into soils, they will assume geotechnical properties similar to those of natural soils. 相似文献
10.
Hülya Boyacioglu 《Environmental monitoring and assessment》2010,167(1-4):115-124
The study comprised modification of the Canadian Council of Ministers of the Environment (CCME) Water Quality Index (CCMEWQI) to obtain a tool in classification of surface waters according to quality defined by the European Legislation—75/440/EEC. Three categories were proposed, and the category ranges of CCMEWQI have been modified depending on the objective chosen. The application of the CCMEWQI with modified categorization scheme was demonstrated to assess overall water quality by integrating observed water quality determinants in the Kucuk Menderes Basin, Turkey. In this scope, the samples analyzed for pH, total dissolved solids (TDS), chlorides (Cl), nitrate–nitrogen (NO3–N), dissolved oxygen (DO), biochemical oxygen demand (BOD5), sulfate (SO4), and boron (B), variables taken monthly over 2 years from the five monitoring sites, were processed. Results revealed that the overall surface water mainly fell within the A2 water class. The CCMEWQI with modified categorization scheme is believed to assist water managers to integrate and interpret the picture of overall water quality based on the European legislation concerning the quality required of surface water intended for the abstraction of drinking water in the Member States (75/440/EEC). 相似文献
11.
In the present study, the influence of aluminium on the regeneration potential of leaf and stem-cuttings of Portulaca oleracea was studied in order to identify a terrestrial plant species as an alternate biomonitoring toolof fresh water environment. The leaves and stem cuttings of theterrestrial plant, P. oleracea grew well in the distilled water producing adventitious and lateral roots. The aluminium treated leaves and stem cuttings showed a reduction in the growthof the adventitious and lateral roots and increase in the decay of leaves and stem cuttings with increasing aluminium concentration. The tolerance index calculated for the leaves and the stem cuttings showed that the leaves were more sensitivethan stems to aluminium. Since all the parameters studied showedconcentration dependent changes, the terrestrial plant, P. oleracea can be considered a suitable biomonitoring tool of fresh water environment besides its usage in the Al toxicity testing. 相似文献
12.
Evaluating the impacts of point source discharges on fish species in estuarine environments can be challenging because of
a paucity of resident species. We evaluated the biology of rock gunnel (Pholis gunnellus) at three relatively uncontaminated sites in the Bay of Fundy, along the Atlantic coast of Canada. Rock gunnel are seasonally
resident (April to November) in tide pools, but little was known about their life history in Atlantic Canada or their potential
for use for monitoring environmental quality. Fish were collected between April and November, and ranged from 2.46 g--15.2~g
in weight and 97 mm-170 mm in length, with a maximum age of 7 years. Both males and females were similar in size, and both
reached sexual maturity at a size of 5.5 g. Organ weights and condition indices of fish were stable from spring when they
returned from offshore (April to May) until late summer (August to September), but fall fish (October to November) had slightly
larger gonads, livers and condition indices. Rock gunnel may be a useful indicator to provide insight into local impacts of
point sources over a short time period. However, they do not provide adequate information on reproductive development and
performance since they are not exposed to onshore contaminants during the periods of gonadal development that have most commonly
found to be sensitive to anthropogenic stressors. 相似文献
13.
The Ephemeroptera family Baetidae is one of the most specious families in the Neotropical region and a great effort to improve
the taxonomy of this group has been made over the last 10 years in South America. Such studies now enable the development
of biomonitoring tools at species-level in the region. A total of 2,199 baetids were collected from seven sampling sites,
collected three times (autumn, winter and summer), representing an environmental gradient, draining an area of Atlantic Forest
remnants. We describe the mesohabitat of nine Baetidae species and evaluate their responses to environmental degradation and
water chemistry by means of biological measures (richness and abundance) and multivariate analysis (Canonical Correspondence
Analysis), in order to assess their potential capacity as indicators of these impacts. Most species were found predominantly
associated with stony substrates, but some were associated with pool litter, and one species was found predominantly in riffle
litter substrate. Species distribution was influenced by the environmental gradient. Based on the CCA ordination, we were
able to identify which species were found in pristine versus the most impaired areas, therefore enabling us to establish the sensitivity of each species. 相似文献
14.
Marappan Jayanthi Selvasekar Thirumurthy Muthusamy Samynathan Muthusamy Duraisamy Moturi Muralidhar Jangam Ashokkumar Koyadan Kizhakkedath Vijayan 《Environmental monitoring and assessment》2018,190(1):51
Climate change impact on the environment makes the coastal areas vulnerable and demands the evaluation of such susceptibility. Historical changes in the shoreline positions and inundation based on projected sea-level scenarios of 0.5 and 1 m were assessed for Nagapattinam District, a low-lying coastal area in the southeast coast of India, using high-resolution Shuttle Radar Topography Mission data; multi-dated Landsat satellite images of 1978, 1991, 2003, and 2015; and census data of 2011. Image processing, geographical information system, and digital shoreline analysis system methods were used in the study. The shoreline variation indicated that erosion rate varied at different time scales. The end point rate indicated the highest mean erosion of ??3.12 m/year, occurred in 73% of coast between 1978 and 1991. Weighted linear regression analysis revealed that the coast length of 83% was under erosion at a mean rate of ??2.11 m/year from 1978 to 2015. Sea level rise (SLR) impact indicated that the coastal area of about 14,122 ha from 225 villages and 31,318 ha from 272 villages would be permanently inundated for the SLR of 0.5 and 1 m, respectively, which includes agriculture, mangroves, wetlands, aquaculture, and forest lands. The loss of coastal wetlands and its associated productivity will severely threaten more than half the coastal population. Adaptation measures in people participatory mode, integrated into coastal zone management with a focus on sub-regional coastal activities, are needed to respond to the consequences of climate change. 相似文献
15.
16.
Zrinka Dragun Željka Fiket Marijana Vuković Biserka Raspor 《Environmental monitoring and assessment》2013,185(3):2603-2614
The possibility of direct measurement of trace elements in hepatic cytosol of European chub (Squalius cephalus) by high-resolution inductively coupled plasma mass spectrometry (HR ICP-MS) after cytosol dilution with Milli-Q water and subsequent acidification was investigated. Due to low detection limits of this procedure, determination of 13 elements (As, Cd, Co, Cu, Fe, Mn, Mo, Pb, Sb, Sn, Sr, V and Zn) was possible in the chub hepatic cytosol, exhibiting excellent measurement repeatability in duplicates. Some of these elements were also measured by HR ICP-MS in acid digested cytosols (Cd, Co, Cu, Fe, Mn, Mo, Sr, V and Zn). Good agreement of the results obtained after sample dilution and sample digestion indicated that complex organic matrix of hepatic cytosol did not affect measurement reliability. Cytosolic concentrations of 13 trace elements in the chub liver were quantified in the following order: Fe, Zn>Cu>Mn>Mo>Sr, V, Cd>Co>As, Pb>Sn>Sb. Unlike Cd, Cu, Fe, Mn and Zn for which the cytosolic concentrations were previously reported after measurement by AAS, cytosolic concentrations of eight additional trace elements characteristic for the liver of chubs inhabiting the low contaminated river water were reported here for the first time (in nanogrammes per gramme)—Mo, 136.8–183.6; Sr, 32.7–63.0; V, 17.5–69.0; Co, 24.3–30.7; As, 9.9–29.5; Pb, 5.8–35.6; Sn, 5.5–12.4; and Sb, 0.9–2.6. The simultaneous measurement of large number of trace elements in the cytosolic fractions of fish tissues, which comprise potentially metal-sensitive sub-cellular pools, could be beneficial as a screening tool in the monitoring of natural waters, because it would enable timely recognition of increased fish exposure to metals. 相似文献
17.
Macrobenthic surveys as a valuable tool for assessing freshwater quality in the Iberian Peninsula 总被引:1,自引:0,他引:1
Julio A. Camargo 《Environmental monitoring and assessment》1993,24(1):71-90
Relationships between natural macrobenthic communities and aquatic environmental conditions have been recently used to perform the Biological Monitoring Water Quality (BMWQ) score system for assessing freshwater quality in the Iberian Peninsula. In this paper, the second version of the BMWQ score system is applied to two selected field studies (organic and nonorganic pollution) in order to illustrate the suitable functional character of this method. The total BMWQ (t-BMWQ) score and the average BMWQ (a-BMWQ) score are calculated, and their relationships with diversity indices are also examined. The BMWQ method appears to be very sensitive to changes in freshwater quality generated by simple organic pollution, but this method appears to be less sensitive to changes generated by complex nonorganic pollution. In addition, both scores are more sensitive measures to assess macroinvertebrate response to organic pollution than total density and diversity indices, exhibiting higher positive coefficients of linear correlation with Camargo's diversity index than with Shannon's and MacArthur's diversity indices. However, the a-BMWQ score is more sensitive to changes in family composition than the t-BMWQ score, whereas this latter score is more sensitive to family richness and sample size. In this sense, the use of the a-BMWQ score is recommended for the biological assessment of freshwater quality degradation in the Iberian Peninsula. More information is obtained for less effort when the a-BMWQ score is used. 相似文献
18.
Koch W Dunkhorst W Lödding H Thomassen Y Skaugset NP Nikano A Vincent J 《Journal of environmental monitoring : JEM》2002,4(5):657-662
The Respicon has been introduced as a sampler for health related measurements of airborne contaminants at workplaces. The instrument is aimed at simultaneous collection of three health related aerosol fractions: (a) the coarser inhalable fraction, defining the aerosol fraction that may enter the nose and mouth during breathing; (b) the intermediate thoracic fraction, defining the fraction that may penetrate beyond the larynx and so reach the lung; and (c) the finer respirable fraction, defining the fraction that may penetrate to gas exchange region of the lung. The instrument has a number of features attractive to occupational hygienists: in addition to providing the three aerosol fractions simultaneously, it is light and compact enough to be used as a personal sampler. yet can be a tripod mounted for area sampling, it can provide samples not only for gravimetric analysis but also microscopic and chemical analyses; and it is also available in a photometric direct-reading version. The instrument has previously been evaluated as an area sampler and, in this mode of operation, has shown reasonable accuracy in collecting respirable, thoracic and inhalable particles, the latter up to particle diameters of ca. 80 microm. Except for some scattered unpublished data there exist no systematic investigations in the Respicon's performance when used as a personal sampler in the industrial environment. In this paper, we will report on a study of side by side comparison of the Respicon with the IOM inhalable sampler, regarded as a reference instrument for the inhalable fraction. The main study was performed at six different workplaces in a nickel refinery. Statistical analysis of the gravimetrically-determined concentration data reveals consistently lower aerosol exposure values for the Respicon as compared to the IOM sampler. The data for the nickel workplaces are compared with findings from other studies. The results are interpreted in the light of the overall results and the possibility of introducing a correction factor is discussed. 相似文献
19.
Adriana C. Bejarano Edwin Levine Alan J. Mearns 《Environmental monitoring and assessment》2013,185(12):10281-10295
The Special Monitoring of Applied Response Technologies (SMART) program was used during the Deepwater Horizon oil spill as a strategy to monitor the effectiveness of sea surface dispersant use. Although SMART was implemented during aerial and vessel dispersant applications, this analysis centers on the effort of a special dispersant missions onboard the M/V International Peace, which evaluated the effectiveness of surface dispersant applications by vessel only. Water samples (n?=?120) were collected from background sites, and under naturally and chemically dispersed oil slicks, and were analyzed for polycyclic aromatic hydrocarbons (TPAHs), total petroleum hydrocarbons (TPH), and a chemical marker of Corexit® (dipropylene glycol n-butyl ether, DPnB). Water chemistry results were analyzed relative to SMART field assessments of dispersant effectiveness (“not effective,” “effective,” and “very effective”), based on in situ fluorometry. Chemistry data were also used to indirectly determine if the use of dispersants increased the risk of acute effects to water column biota, by comparison to toxicity benchmarks. TPAH and TPH concentrations in background, and naturally and chemically dispersed samples were extremely variable, and differences were not statistically detected across sample types. Ratios of TPAH and TPH between chemically and naturally dispersed samples provided a quantitative measure of dispersant effectiveness over natural oil dispersion alone, and were in reasonable agreement with SMART field assessments of dispersant effectiveness. Samples from “effective” and “very effective” dispersant applications had ratios of TPAH and TPH up to 35 and 64, respectively. In two samples from an “effective” dispersant application, TPHs and TPAHs exceeded acute benchmarks (0.81 mg/L and 8 μg/L, respectively), while none exceeded DPnB’s chronic value (1,000 μg/L). Although the primary goal of the SMART program is to provide near real-time effectiveness data to the response, and not to address concerns regarding acute biological effects, the analyses presented here demonstrate that SMART can generate information of value to a larger scientific audience. A series of recommendations for future SMART planning are also provided. 相似文献
20.
Freshwater leeches (Hirudinea) as a screening tool for detecting organic contaminants in the environment 总被引:1,自引:0,他引:1
In earlier work, we found that leeches from an industrially polluted creek bioaccumulated chlorophenols to much higher concentrations than other resident benthic invertebrates and fish. We suggested that leeches may have significant potential as biomonitors for these and other organic contaminants in the environment. In this study, we compared the bioaccumulation and depuration of 16 organic compounds, including eight chlorophenols (CPs), lindane, DDT and four derivatives, benzothiazole (BT) and 2-(Methylthio)benzothiazole (MMBT) for three species of leeches. Dina dubia had the highest bioaccumulation capacity for most contaminants, but residues persisted longest in Erpobdella punctata. Helobdella stagnalis appeared capable of degrading some compounds. Half lives of CPs, DDT and DDT derivatives were generally longer than one month. In contrast, half lives were only 1 day for lindane, 1–2.5 days for MMBT and 7 days for BT despite very high initial tissue concentrations of the latter two compounds. Bioconcentration factors for contaminants in leeches were higher than those reported for other aquatic organisms. Half lives for lindane, DDT and DDT derivatives were consistent with the literature for other organisms, but half lives for CPs were much longer. The results suggest that leeches would be excellent biomonitors of both continuous and intermittent contamination of a waterway with CPs and DDT, as they retain these compounds for long periods after exposure. Their usefulness as a screening tool for lindane and benzothiazoles would be limited to chronically contaminated environments. 相似文献