Intra- and intercompartmental associations between levels of organochlorines in maternal plasma, cord plasma and breast milk, and lead and cadmium in whole blood, for indigenous peoples of Chukotka, Russia

Long-range transport of pollutants towards circumpolar regions emphasizes the need for up-to-date and reliable biological monitoring data. This paper explores the use, reliability and availability of maternal blood (MB) and plasma (MP), cord blood (CB) and plasma (CP) and mother's milk (MM) in terms of assessing exposure to persistent toxic substances (PTSs). It is concluded that MP has the best combination of availability, sensitivity in terms of number of PTSs, their detection frequency and concentrations, and physiological relevance. The study group consisted of 48 pregnant women of indigenous origin from the Chuchki district in the eastern Russian arctic. Blood, CB and MM specimens were collected from all women and MP, CP and MM were analyzed for the Arctic Monitoring and Assessment Programme (AMAP) suite of organochlorines (OCs) and metals (Pb and Cd in MB and CB). Generally speaking, the levels of PTSs coincided with those indicated in several AMAP publications from Chukotka and other areas of northern Russia. The correlations of PTS concentrations between the three body fluid compartments exceeded the minimum statistical requirements of alpha = 0.05 and beta = 0.20 for most of the compounds, with r > 0.46 except for Cd (r = 0.05); lipid adjustments for the OCs did not affect the r-values to any significant extent. The majority of the inter-OC correlations within compartments also fulfilled the indicated statistical condition. Careful consideration is given to the replacement of concentrations below the detection limit, OC detection frequency, the criteria for log-transformation of the data, analytical uncertainty, and biological variability. Practical implications of the findings are explored.     

Global climate change and contaminants--an overview of opportunities and priorities for modelling the potential implications for long-term human exposure to organic compounds in the Arctic

This overview seeks to provide context and insight into the relative importance of different aspects related to global climate change for the exposure of Northern residents to organic contaminants. A key objective is to identify, from the perspective of researchers engaged in contaminant fate, transport and bioaccumulation modelling, the most useful research questions with respect to projecting the long-term trends in human exposure. Monitoring studies, modelling results, the magnitude of projected changes and simplified quantitative approaches are used to inform the discussion. Besides the influence of temperature on contaminant amplification and distribution, accumulation of organic contaminants in the Arctic is expected to be particularly sensitive to the reduction/elimination of sea-ice cover and also changes to the frequency and intensity of precipitation events (most notably for substances that are highly susceptible to precipitation scavenging). Changes to key food-web interactions, in particular the introduction of additional trophic levels, have the potential to exert a relatively high influence on contaminant exposure but the likelihood of such changes is difficult to assess. Similarly, changes in primary productivity and dynamics of organic matter in aquatic systems could be influential for very hydrophobic contaminants, but the magnitude of change that may occur is uncertain. Shifts in the amount and location of chemical use and emissions are key considerations, in particular if substances with relatively low long range transport potential are used in closer proximity to, or even within, the Arctic in the future. Temperature-dependent increases in emissions via (re)volatilization from primary and secondary sources outside the Arctic are also important in this regard. An increased frequency of boreal forest fires has relevance for compounds emitted via biomass burning and revolatilization from soil during/after burns but compound-specific analyses are limited by the availability of reliable emission factors. However, potentially more influential for human exposure than changes to the physical environment are changes in human behaviour. This includes the gradual displacement of traditional food items by imported foods from other regions, driven by prey availability and/or consumer preference, but also the possibility of increased exposure to chemicals used in packaging materials and other consumer products, driven by dietary and lifestyle choices.     

Assessment of prenatal exposure to persistent organohalogen compounds from cord blood serum analysis in two Mediterranean populations (Valencia and Menorca)

Prenatal levels of organohalogen compounds (OHCs), including polybromodiphenyl ethers (PBDEs), polychlorobiphenyls (PCBs), hexachlorobenzene (HCB), hexachlorocyclohexanes and DDTs, have been investigated in two different cohorts from the Spanish Mediterranean area, Valencia and Menorca, by analysis of cord blood serum. Comparison of the observed median concentrations to other cohorts shows low PBDE levels (2.8-6.5 ng g(-1) lipid) but high values of HCB (0.68 ng ml(-1), 260 ng g(-1) lipid) and PCBs (0.65 ng ml(-1), 240 ng g(-1) lipid) in the cohort of Menorca indicating that Mediterranean areas, and not only high latitude regions, may contain population groups highly exposed to some of these pollutants. Significant differences in the concentrations of these compounds have been found between the two cohorts. Differences in maternal population such as age or body mass index cannot explain this variation. One possible cause of variability is the seven year time period elapsed between the two cohort recruitments but the strong differences observed do not allow exclusion of local diet differences. Thus, the different average PCB congener distributions between the two cohorts suggest an influence from materials containing diverse PCB mixtures. The congener mixtures found in Menorca could reflect a diet contribution from some western Mediterranean fish species. These results provide baseline information on prenatal OHC background levels in the Mediterranean area.     

Concentrations of Cadmium, Mercury and Selenium in Blood, Liver and Kidney of Common Eider Ducks from the Canadian Arctic

We determined concentrations of selected trace elements inlivers, kidneys and blood samples from common eiders (Somateria mollissima borealis) from the eastern Canadianarctic during 1997 and 1998. Concentrations of totalmercury and organic mercury were generally low in the liversof these birds (less than 6 and 4 g g^–1 dry wt,respectively). Selenium ranged between 11–47 g g^–1 inlivers. Renal cadmium concentrations were among the highestever published for this species (range: 47–281 g g^–1). The regressions of log-transformed concentrations ofthese trace elements in blood samples on those in liver orkidney were significant (all P-values < 0.05) andpositive. However, except for organic mercury (RM ² = 0.83), the co-efficients of determination were low tomoderate (range of R ²: 0.26–0.52), suggesting poorto moderate predictive capability. Furthermore, therelationships between total mercury in blood and liverchanged between 1997 and 1998, suggesting that it would notbe possible to predict consistently, concentrations ofmercury in blood from those in liver based on samples takenin one year. Blood samples can be used to determineconcentrations of these trace elements in common eiders (andprobably other sea duck species as well). The use of bloodsamples is especially warranted when it is undesirable tokill the animal such as when working with rare or endangeredsea duck species or when the objective is to relate traceelement exposure to annual survival rates. However, thepredictive equations developed here should not be used topredict expected concentrations in one type of tissue fromthose in the other.     

Determination of arsenic species in fish, crustacean and sediment samples from Thailand using high performance liquid chromatography (HPLC) coupled with inductively coupled plasma mass spectrometry (ICP-MS)

Suitable techniques have been developed for the extraction of arsenic species in a variety of biological and environmental samples from the Pak Pa-Nang Estuary and catchment, located in Southern Thailand, and for their determination using HPLC directly coupled with ICP-MS. The estuary catchment comprises a tin mining area and inhabitants of the region can suffer from various stages of arsenic poisoning. The important arsenic species, AsB, DMA, MMA, and inorganic arsenic (As III and V) have been determined in fish and crustacean samples to provide toxicological information on those fauna which contribute to the local diet. A Hamilton PRP-X100 anion-exchange HPLC system employing a step elution has been used successfully to achieve separation of the arsenic species. A nitric acid microwave digestion procedure, followed by carrier gas nitrogen addition- (N2)-ICP-MS analysis was used to measure total arsenic in sample digests and extracts. The arsenic speciation of the biological samples was preserved using a Trypsin enzymatic extraction procedure. Extraction efficiencies were high, with values of 82-102%(As) for fish and crustacean samples. Validation for these procedures was carried out using certified reference materials. Fish and crustacean samples from the Pak Pa-Nang Estuary showed a range for total arsenic concentration, up to 17 microg g(-1) dry mass. The major species of arsenic in all fauna samples taken was AsB, together with smaller quantities of DMA and, more importantly, inorganic As. For sediment samples, arsenic species were determined following phosphoric acid (1 M H3PO4) extraction in an open focused microwave system. A phosphate-based eluant, pH 6-7.5, with anion exchange HPLC coupled with ICP-MS was used for separation and detection of AsIII, AsV, MMA and DMA. The optimum conditions, identified using an estuarine sediment reference material (LGC), were achieved using 45 W power and a 20 minute heating period for extraction of 0.5 g sediment. The stability and recovery of arsenic species under the extraction conditions were also determined by a spiking procedure which included the estuarine sediment reference material. The results show good stability for all species after extraction with a variability of less than 10%. Total concentrations of arsenic in the sediments from the Pak Pa-Nang river catchment and the estuary covered the ranges 7-269 microg g(-1)and 4-20 [micro sign]g g(-1)(dry weight), respectively. AsV was the major species found in all the sediment samples with smaller quantities of AsIII. The presence of the more toxic inorganic forms of arsenic in both sediments and biota samples has implications for human health, particularly as they are readily 'available'.     

2010—2019年衡阳市大气降尘污染特征及变化趋势分析

利用2010—2019年衡阳市城区大气降尘监测数据,研究分析降尘时间、空间污染特征,并采用秩相关系数法定量分析污染变化趋势.结果表明:大多数年份衡阳市城区大气降尘污染程度较轻,上半年降尘量低于下半年,交通区降尘量对市城区总体的影响最大;秩相关系数法定量分析得出居民区降尘污染呈加重趋势、且污染变化趋势具有显著意义,商业区...     

Assessment of the levels of DDT and DDE in soil and blood samples from Tabasco, Mexico

In Mexico, 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) was used until the year 2000, principally in agriculture and anti-paludal program health campaigns. The southeastern region of Mexico was an important area of malaria, and from 1957 DDT was applied indoors every 6?months, with a coverage of 2?g/m². The current study was performed in Tabasco, a Mexican state located in the southeastern region of Mexico. DDT and 1,1-dichloro-2,2-bis(4-chlorophenyl)ethene (DDE) were analyzed by gas chromatography/mass spectrometry. In general, low levels were found in household outdoor samples; the levels of DDT ranged from not detectable to 0.048?mg/kg, and of DDE from 0.001 to 0.068?mg/kg. An important finding was that, in all communities where DDT in blood was analyzed, exposure to DDT was found, indicating both past and present exposure. Although the levels found in this study were lower than other studies in Mexico, there is a need to evaluate whether the people living in the study area are at risk.     

Cytogenetic evaluation and the association with polymorphisms of the CPY1A1 and NR1I3 genes in individuals exposed to BTEX

The gas station attendants are exposed daily to chemical agents that compose gasoline, such as BTEX (benzene, toluene, ethylbenzene, and xylene), and the exposure to these agents can cause a variety of effects on the human health. Among the various possible cell alterations associated with these exposures are the formation of micronuclei and of binucleated cells which are used as indicators of clastogenic action. Benzene, the main carcinogenic agent, is metabolized to more soluble forms and easily excreted by isoenzymes of cytochrome P450, such as CYP1A1. The CYP1A1 gene is highly polymorphic and one of its allele variations can be detected by the use of restriction endonucleasis MspI and is originated by the transition of a thymine by a cytosine (3798T>C), resulting in the polymorphic allele CYP1A1*2A. The objective of this study was to evaluate the cytogenetic damage induced by the exposure to BTEX and to associate it with the polymorphisms of the CYP1A1 and NR1I3 genes. Samples of exfoliated cells from the oral mucosa of 27 gas station attendants and from a control group were collected. The results found show that the group exposed to BTEX presents significantly higher alterations than those in the control group for micronuclei (MN; 6.85?±?1.33 vs. 2.96?±?1.91, P?<?0.001) and for the total of nuclear alterations observed (MN + binucleated cells (BNC); 9.59?±?4.73 vs. 5.07?±?2.21, P?<?0.001). When comparing the cytological alterations and the genotypes among the exposed individuals for the polymorphism 3798T>C of the CYP1A1 gene, homozygotes TT present MN + BNC significantly higher than carriers of the allele C (10.88?±?5.36 vs. 5.33?±?2.52, P?=?0.028). No association was observed in the control group or for the NR1I3 gene. These results show that molecular and cytogenetic data can be used in the future as tools to monitor individuals exposed to such compounds.     

Effect of high sulfate concentration on the corrosivity: a case study from groundwater in Harran Plain, Turkey

Corrosion, which tends to increase the concentrations of certain metals in tap water, is one of the most important water quality problems as it can affect public health and public acceptance of water supply and the cost of providing safe water. In this context, this study aimed at investigating the scale formation tendency or corrosivity of groundwater in the semi-arid Harran Plain. The degree of scale formation tendency/corrosivity of water was determined considering pHs, Langelier Index, and Ryznar Index of groundwater samples. Except for well no.4, which is close to a local hot spring, all the wells had corrosive characteristics. The amount of CO₂ from the soil zone respiration and high sulfate concentration in the wells are important factors affecting corrosiveness. Results showed that precipitation, excessive irrigation, and change in groundwater level caused seasonal variation in corrosive characteristics.     

A study on Aspergillus species in houses of asthmatic patients from Sari City, Iran and a brief review of the health effects of exposure to indoor Aspergillus

To study the distribution of Aspergillus spp. in outdoor and indoor air of asthmatic patients’ houses, as well as a review on the health effects of exposure to indoor Aspergillus. Open plates containing malt extract agar media were used to isolate fungi from the indoor (n?=?360) and outdoor (n?=?180) air of 90 asthmatic patients’ houses living in Sari City, Iran. Plates were incubated at room temperature for 7–14 days. Cultured Aspergillus spp. were identified by standard mycological techniques. All culture plates grew fungi, a testament to the ubiquitous nature of fungal exposure. Cladosporium spp. (29.2%), Aspergillus spp. (19.0%), and Penicillium spp. (18.3%) were most common inside the houses while Cladosporium spp. (44.5%), Aspergillus spp. (12.4%), and Alternaria spp. (11.1%) were most common outside the houses. Aspergillus flavus (30.1%) and A. fumigatus (23.1%) are the most commonly isolated species in indoor air. Aspergillus flavus (44.5%) and A. fumigatus (42.6%) were the most prevalent Aspergillus spp. outside. The most colony numbers of Aspergillus were isolated from kitchens (30.4%) and the least from bedrooms (21.1%). Aspergillus flavus was the most prevalent specie in all sampled rooms except in the kitchen where A. fumigatus was the most common. Aspergillus flavus is the most prevalent species among the Aspergillus spp. in the indoor and outdoor of a warm climate area. In these areas, A. flavus can be a major source of allergen in the air. Therefore, minimizing indoor fungal exposure could play an important role in reducing allergic symptoms in susceptible persons.     

Analysis of the spatial-temporal variation characteristics of vegetative drought and its relationship with meteorological factors in China from 1982 to 2010

Drought is a complex natural phenomenon that can cause reduced water supplies and can consequently have substantial effects on agriculture and socioeconomic activities. The objective of this study was to gain a better understanding of the spatial-temporal variation characteristics of vegetative drought and its relationship with meteorological factors in China. The Vegetation Condition Index (VCI) dataset calculated from NOAA/AVHRR images from 1982 to 2010 was used to analyse the spatial-temporal variation characteristics of vegetative drought in China. This study also examined the trends in meteorological factors and their influences on drought using monitoring data collected from 686 national ground meteorological stations. The results showed that the VCI appeared to slowly rise in China from 1982 to 2010. From 1982 to 1999, the VCI rose slowly. Then, around 2000, the VCI exhibited a severe fluctuation before it entered into a relatively stable stage. Drought frequencies in China were higher, showing a spatial distribution feature of “higher in the north and lower in the south”. Based on the different levels of drought, the frequencies of mild and moderate drought in four geographical areas were higher, and the frequency of severe drought was higher only in ecologically vulnerable areas, such as the Tarim Basin and the Qaidam Basin. Drought was mainly influenced by meteorological factors, which differed regionally. In the northern region, the main influential factor was sunshine duration, while the other factors showed minimal effects. In the southern region and Tibetan Plateau, the main influential factors were sunshine duration and temperature. In the northwestern region, the main influential factors were wind velocity and station atmospheric pressure.     

Spatial variability of air pollutants in the city of Taranto, Italy and its potential impact on exposure assessment

Epidemiological studies typically use monitored air pollution data from a single station or as averaged data from several stations to estimate population exposure. In industrialized urban areas, this approach may present critical issues due to the spatial complexities of air pollutants which are emitted by different sources. This study focused on the city of Taranto, which is one of the most highly industrialized cities in southern Italy. Epidemiological studies have revealed several critical situations in this area, in terms of mortality excess and short-term health effects of air pollution. The aims of this paper are to study the variability of air pollutants in the city of Taranto and to interpret the results in relation to the applicability of the data in assessing population exposure. Meteorological and pollution data (SO2, NO2, PM10), measured simultaneously and continuously during the period 2006–2010 in five air quality stations, were analyzed. Relative and absolute spatial concentration variations were investigated by means of statistical indexes. Results show significant differences among stations. The highest correlation between stations was observed for PM10 concentrations, while critical values were found for NO2. The worst values were observed for the SO2 series. The high values of 90th percentile of differences between pairs of monitoring sites for the three pollutants index suggest that mean concentrations differ by large amounts from site to site. The overall analysis supports the hypothesis that various parts of the city are differently affected by the different emission sources, depending on meteorological conditions. In particular, analysis revealed that the influence of the industrial site may be primarily identified with the series of SO2 data which exhibit higher mean concentration values and positive correlations with wind intensity when the monitoring station is downwind from the industrial site. Results suggest evaluating the population exposure to air pollutants in industrialized cities by taking into account the possible zones of influence of different emission sources. More research is needed to identify an indicator, which ought to be a synthesis of several pollutants, and take into account the meteorological variables.     

A pilot study on the determination of perfluorooctanesulfonate and other perfluorinated compounds in blood of Canadians

A pilot study was conducted to provide preliminary data on the concentrations of perfluorooctanesulfonate (PFOS), perfluorooctanoic acid (PFOA) and perfluorooctanesulfonamide (PFOSA) in the blood of Canadians. A set of 56 human serum samples was collected from non-occupationally exposed Canadians and analyzed by microbore HPLC-negative ion electrospray tandem mass spectrometry. PFOS was the main component of perfluorinated organic compounds (PFCs) and was detected in all 56 blood specimens at an average concentration of 28.8 ng mL(-1) and a range from 3.7 to 65.1 ng mL(-1). The concentration of PFOA was an order of magnitude lower than that of PFOS and was found only in 16 samples (29%) at concentrations above the limit of quantification (LOQ). PFOSA was not detected at levels above the method detection limit (MDL) in any of the samples. The levels of PFCs observed in the sample group of non-occupationally exposed humans in Canada were similar to the levels reported in a previous US study with a similar sample pool size. Two distinct PFOS isomers in human serum were identified by accurate mass determination.     

Biomonitoring for exposure to multiple trace elements via analysis of urine from participants in the study of metals and assisted reproductive technologies (SMART)

Humans are exposed to concentrations of multiple trace elements through a variety of background sources; many are suspected reproductive toxicants. Prior to investigating associations between trace elements and human reproductive health, potential biomarkers of exposure should be characterized by sources of variability in the population at risk. Factors influencing elemental exposure should also be identified to ensure their consideration as potential confounding variables. The principal aim of this study is to characterize sources of variability for 19 trace elements measured in urine specimens collected from 55 women and 36 male partners completing a 1st cycle of in vitro fertilization (IVF). Urine specimens were analyzed using a biomonitoring method based on inductively coupled plasma-mass spectrometry (ICP-MS). Randomly selected urine specimens (～6%) were analyzed in duplicate, and these data were used to characterize sources of variability. Nine trace elements including As, Ba, Cd, Cs, Co, Cu, Mn, Mo, and Zn, were quantified in most specimens, indicating their utility in future epidemiologic studies of trace elements exposure and IVF outcomes. With few exceptions, normalizing urine using the traditional creatinine-correction procedure, or an alternative approach based on a linear regression model, increased residual variability only slightly. Sex and race appear to be important factors to consider in epidemiologic studies conducted in this population. Urine concentrations for most elements are similar to those reported in the 2005-2006 National Health and Nutrition Examination Survey (NHANES); however, differences in others may indicate regional trends or a unique exposure history for this infertile study population.     

Ozone influence on native vegetation in the Jizerske hory Mts. of the Czech Republic: results based on ozone exposure and ozone-induced visible symptoms

Ozone levels in the Jizerske hory Mts. measured at 13 sites by diffusive samplers during the 2006 and 2007 vegetation seasons are presented. A significant ozone gradient (5.4 ppb in 2006 and 4.0 ppb in 2007) per 100 m difference in altitude between 370 and 1,100 m a.s.l. was recorded. High-resolution maps of phytotoxic potential were developed. The AOT40 threshold (5 ppm h) was exceeded over the entire area with the highest levels exceeding this threshold by 12 times in the upper portions of the mountains. Ozone visible injury was evaluated at four of the monitoring sites on seven native plant and tree species. Four species showed ozone-like symptoms, two of which (Rubus idaeus and Fagus sylvatica) were confirmed as ozone-induced. Our results indicate that ambient ozone is likely to have a much lower impact on the Jizerske hory Mts. vegetation than expected, considering the measured ambient ozone exposures and favourable environmental conditions for ozone uptake.     

Effects of long-term irrigation with treated wastewater on soil quality,soil-borne pathogens,and living organisms: case study of the vicinity of El Hajeb (Tunisia)

Medium (i.e. 15 years) and long-term (i.e. 20 years) impact of irrigation using secondary-treated municipal wastewater (TWW) was assessed on two agricultural soil samples, denoted by E and G, respectively, in the vicinity of El Hajeb region (Southern Tunisia). Soil pH, electrical conductivity particle size grading, potential risk of salinity, water holding capacity and chemical composition, as well as organic matter content, pathogenic microorganisms and heavy metal concentrations in the TWW-irrigated (E and G) and rainwater-irrigated (T) soils at various depths, were monitored and compared during a 5-year experiment. Our study showed that bacterial abundance is higher in sandy–clayey soil, which has an enhanced ability to retain moisture and nutrients. The high level of bacterial flora in TWW-irrigated soils was significantly (p?<?0.05) correlated (r?=?~0.5) with the high level of OM. Avoidance assays have been used to assess toxic effects generated by hazards in soils. The earthworms gradually avoided the soils from the surface (20 cm) to the depth (60 cm) of the G transect and then the E transect, preferring the T transect. The same behaviour was observed for springtails, but they seem to be less sensitive to the living conditions in transects G and E than the earthworms. The avoidance response test of Eisenia andrei was statistically correlated with soil layers at the sampling sites. However, the avoidance response test of Folsomia candida was positively correlated with silt-clay content (+0.744*) and was negatively correlated with sand content (?0.744*).     

Very high concentrations of DDE and toxaphene residues in crocodiles from the Ord River, Western Australia: an investigation into possible endocrine disruption

Organochlorine pesticide concentrations, particularly those of the DDT family and of toxaphene, were measured by gas chromatography in samples of liver and body fat taken from Australian freshwater crocodiles Crocodylus johnstoni at three locations along the Ord River in Western Australia. The three sampling sites were the irrigation area, downstream of the irrigation area, and well upstream of the irrigation area; the last site serving as the control. DDT and toxaphene were applied in large and known quantities to cotton grown in the Ord Irrigation Area from 1964 to 1974. Thus the residues in the crocodile tissues are representative of the situation almost thirty years after the use of DDT and toxaphene ceased in the area. Very high concentrations of p,p'-DDE and toxaphene were found in the lipid-rich tissues that were examined. Livers and body fat from estuarine crocodiles Crocodylus porosus from the downstream site were also analysed. As p,p'-DDE and toxaphene are both known to be disruptive of endocrine systems, a range of blood parameters, including estradiol and testesterone concentrations, were also measured for all the animals studied. The ovaries and testes of the freshwater crocodiles were also examined histologically. There were no obvious effects on blood chemistry or gonad histology of the large burden of pesticides and their metabolites carried by exposed animals, although the limited number of samples and the variability of the breeding state of the animals examined may have masked possible effects. The isolation of the area, the accurately known applications of DDT and toxaphene, and the simplicity of the drainage system make the lower Ord River a unique natural laboratory for studying the long term breakdown and effects of pesticides applied in a tropical environment.     

Analysis of some heavy metals in the riverine water, sediments and fish from river Ganges at Allahabad

The river Ganges has been one of the major recipients of industrial effluents in India. The present paper deals with the study related to occurrence and bioaccumulation of heavy metals (Cu, Cr, Cd, Pb, Zn) in the riverine water, sediment, and the muscles of two cat fish species, Channa punctatus (C. punctatus) and Aorichthys aor (A. aor) procured from the river Ganges at Allahabad. The data obtained after water analysis reflected the order of occurrence of heavy metals to be Zn > Pb > Cu > Cr > Cd, respectively. The analysis of heavy metals in sediment indicated that among the five heavy metals tested; Zn was maximally accumulated followed by Pb, Cr, Cu and Cd. The trend of heavy metals accumulation in fish muscles was found to be similar to that observed in sediment and water such as Zn > Pb > Cu > Cr > Cd. Data indicated that Zn accumulated maximally in the sediment as well as muscles of both of the fish species in comparison to other metals.