Seasonal variation of heavy metals in ambient air and precipitation at a single site in Washington, DC

Atmospheric samples of precipitation and ambient air were collected at a single site in Washington, DC, for 7 months (for ambient air samples) and 1 year (for wet deposition samples) and analyzed for arsenic, cadmium, chromium and lead. The ranges of heavy metal concentrations for 6-day wet deposition samples collected over the 1-year period were 0.20-1.3 microg/l, 0.060-5.1 microg/l, 0.062-4.6 microg/l and 0.11-3.2 microg/l for arsenic, cadmium, chromium and lead, respectively, with a precision better than 5% for more than 95% of the measurements. The ranges of heavy metal concentrations for the 6-day ambient air samples were 0.800-15.7 ng/m(3), 1.50-30.0 ng/m(3), 16.8-112 ng/m(3), and 2.90-137 ng/m(3) for arsenic, cadmium, chromium and lead, respectively, with a precision better than 10%. The spread in the heavy metal concentration over the observation period suggests a high seasonal variability for heavy metal content in both ambient air and wet deposition samples.     

Residual levels of DDTs and PAHs in freshwater and marine fish from Hong Kong markets and their health risk assessment

Axial and ventral muscle from 10 each species of freshwater and marine fish purchased from markets in Hong Kong were analyzed for dichlorodiphenyltrichloroethane (total DDTs including DDE, DDD and DDT) and polycyclic aromatic hydrocarbons (PAHs). Among the 10 freshwater fish species, rice field eel (Monopterus albus) showed significantly higher levels of DDTs in both ventral (125 ng/g wet wt) and axial muscle (127 ng/g wet wt) than the other species. The highest concentration of PAHs was detected in catfish (Clarias fuscus), with 24.8 ng/g in ventral muscle and 9.1 ng/g in axial muscle. As to marine fish, snubnose pompano (Trachinotus blochii) showed significantly higher levels of DDT and its metabolites (1018 ng/g in ventral and 409 ng/g wet wt in axial tissues) than all other marine fish species. The overall concentrations of PAHs in marine fish species were 15.5-57.0 ng/g (axial muscle) and 18.1-118 ng/g wet wt (ventral muscle) where yellow seafin (Acanthopeyrus latus) and golden threadfin bream (Nemipterus virgatus) exhibited the highest concentrations of PAHs in the axial and ventral muscles, respectively. In general, results showed that levels of PAHs in Hong Kong market fish was low and do not expect to cause any concern for human consumption. However, the levels of DDTs in fish samples ranged from 1.10 to 1018 ng/g wet wt, and based on a fish consumption rate of 142.2g/day to calculate the screening value of 14.4 ng/g wet wt for human consumption (USEPA, 2000. Guidance for assessing chemical contaminant, data for use in fish advisories, vol. 1: fish sampling and analysis, third ed. EPA 823-R-95-007. Office of Water, Washington, DC), there were 9 out of 20 (45%) muscle samples of freshwater fish species and 14 out of 20 (70%) muscle samples of marine fish species had elevated levels of DDTs exceeded the screening value. It was also suggested to use ventral muscle for detecting concentrations of persistent organic pollutants in fish.     

Mosses as biomonitors of atmospheric heavy metal deposition: Spatial patterns and temporal trends in Europe

In recent decades, mosses have been used successfully as biomonitors of atmospheric deposition of heavy metals. Since 1990, the European moss survey has been repeated at five-yearly intervals. Although spatial patterns were metal-specific, in 2005 the lowest concentrations of metals in mosses were generally found in Scandinavia, the Baltic States and northern parts of the UK; the highest concentrations were generally found in Belgium and south-eastern Europe. The recent decline in emission and subsequent deposition of heavy metals across Europe has resulted in a decrease in the heavy metal concentration in mosses for the majority of metals. Since 1990, the concentration in mosses has declined the most for arsenic, cadmium, iron, lead and vanadium (52-72%), followed by copper, nickel and zinc (20-30%), with no significant reduction being observed for mercury (12% since 1995) and chromium (2%). However, temporal trends were country-specific with sometimes increases being found.     

Distribution of chromium, cadmium, nickel and lead in agricultural soils collected from Kazanli-Mersin, Turkey

This study reports total levels of chromium, cadmium, nickel and lead in the agricultural land adjacent a factory producing chromate compounds in Kazanli-Mersin. Surface soil samples were collected from fields around the factory as well as from fields farther away to measure contamination due to aerial transportation and deposition of dust produced in the industrial process. Heavy metals in soil were extracted using wet digestion, and concentrations were measured by atomic absorption spectrophotometry. The concentrations were compared with Turkish maximum allowable concentration values. The metal concentrations averaged 80, 0.14, 228 and 431mg1kg^-1 for chromium, cadmium, nickel and lead, respectively. Soil samples contaminated with chromium were mainly found 500–20001m from the factory and decreased with increasing distance from the factory. Elevated chromium and nickel concentrations were determined in the soils around the factory, especially to the northwest (prevailing wind) and west. Lead concentrations exceeded the limit in only roadside soils (4000 and 50001m to the west), but tended to increase in the vicinity of industrial activity (especially in the west, the northwest and the north). The cadmium concentration did not exceed the limit and was within the normal range for soils.     

Human health risk assessment of organochlorines associated with fish consumption in a coastal city in China

Food consumption is an important route of human exposure to organochlorines (OCs). In order to assess the potential health risks associated with these contaminants due to fish consumption, five species of fish were collected from a local market in Zhoushan City, an island in the East China Sea. Dioxin-like compounds, such as polychlorinated dibenzo-p-dioxins/ dibenzofurans, in the fish samples were screened by H4IIE-luc cell bioassay, and the concentrations of specific organochlorines were measured by gas chromatograph-electron capture detector (GC-ECD). The bioassay results indicated that concentrations of dioxin-like compounds in the fish samples were below detection limit (0.64 pg/mL). The concentrations of OC pesticides and PCBs ranged from 0.67 to 13 and 0.24 to 1.4 ng/g wet wt., respectively. Significantly, concentrations of p,p'-DDE in fish meat were comparatively high (average 3.9 ng/g wet wt.) compared with the other OC pesticides. The daily fish consumption, based on a dietary survey conducted among 160 local healthy residents, was determined to be 105 g/person. The relevant cancer benchmark concentrations of HCB, dieldrin, chlordane, DDTs and PCBs were 0.36, 0.04, 1.6, 1.7, and 0.29 ng/kg per day, respectively, based on the local diet. The hazard ratios (HRs), based on non-cancer endpoints were all less than 1.0, while the HRs based on cancer were greater than 1.0 for certain contaminants based on the 95th centile concentration in fish tissue.     

Butyltin compounds in sediment and fish from the Polish Coast of the Baltic Sea

Concentrations of mono- (MBT), di- (DBT), and tri-(TBT) butyltin compounds were measured in eggs, liver, and muscle of nine species of fish from four regions of the Baltic Sea - the Firth of Vistula, the Gulf of Gdańsk, Puck Bay, and the mouth of the Vistula River. The overall concentration ranges among all the fish sampled from the four sites were: < 7 to 79 ng/g for MBT, 6 to 1100 ng/g for DBT, 7 to 3600 ng/g for TBT, and 16 to 4800 ng/g for total BTs, on a wet wt basis. The highest concentration of total BTs was found in herring liver from the Firth of Vistula (4800 ng/g, wet wt) and in roach muscle from Puck Bay (3300 ng/g, wet wt), while the least concentration was found in burbot eggs and liver from the Vistula River (39 and 32 ng/g, wet wt, respectively). TBT was the major form of BTs present in most samples analyzed. Sediment samples collected from shipyards in the Gulf of Gdańsk contained butyltin concentrations ranging from 1.2 to 46 μg/g (dry wt) for MBT, 2.0 to 42 μg/g for DBT, and 2.6 to 40 μg/g for TBT. As with the fish, the majority of the BTs in sediment were present as TBT, which suggested recent exposure of the aquatic environment of the region to TBT.     

Methylmercury and total mercury in estuarine organisms from Rio de Janeiro, Brazil

Guanabara Bay (GB), located in the Rio de Janeiro State, is still a productive estuary on the south-eastern Brazilian coast. It is an ecosystem heavily impacted by organic matter, oil and a number of other toxic compounds, including Hg. The present study aimed to comparatively evaluate the aquatic total mercury (THg) and MeHg contamination, and the ratios of MeHg to THg (% MeHg), in 3 species of marine organisms, Micropogonias furnieri-carnivorous fish (N = 81), Mugil spp.--detritivorous fish (N = 20) and Perna perna--filter-feeding bivalves (N = 190), which are widely consumed by the population. A total of 291 specimens were collected at the bay in different periods between 1988 and 1998. THg concentrations were determined by cold vapour AAS with stannous chloride as a reducing agent. MeHg was extracted by dithizone-benzene and measured by GC-ECD. Analytical quality was checked through certified standards. All organisms presented both low THg and MeHg concentrations and they were below the maximum limit of 1,000 micrograms Hg.kg-1 wet wt. as established for human intake of predatory fish by the new Brazilian legislation. Carnivorous fish showed higher THg and MeHg concentrations, and also % MeHg in muscle tissues, than organisms with other feeding habits and lower trophic levels. The average of THg concentrations in carnivorous fish was 108.9 +/- 58.6 micrograms.kg-1 wet wt. (N = 61) in 1990 and 199.5 +/- 116.2 micrograms.kg-1 wet wt. (N = 20) in 1998, but they presented different total length and body weights. The average THg content in detritivorous fish was 15.4 +/- 5.8 micrograms.kg-1 wet wt., whereas THg concentrations ranged from 4.1 to 53.5 micrograms.kg-1 wet wt. for the molluscs. The THg and MeHg contents of mussel varied according to the sampling point and water quality. MeHg concentration in detritivorous fish was similar to MeHg concentration in molluscs, but there was a significant difference in the MeHg/THg ratio: the carnivorous fish presented higher MeHg percentages (98%) than the detritivorous fish (54%) and the molluscs (33%). Weight-normalised average concentration of THg in carnivorous fish collected in 1990 (0.18 +/- 0.08 microgram.g-1/0.7 kg wet wt.) and in 1998 (0.16 +/- 0.09 microgram.g-1/0.7 kg wet wt.) presented no significant difference (t = 1.34; P < 0.5). In conclusion, the low THg and MeHg concentrations in the organisms from the GB ecosystem, are related to its eutrophic conditions and elevated amounts of suspended matter. In this situation, Hg could be strongly complexed or adsorbed by the particulate, which would dilute the Hg inputs and reduce its residence time in the water column, with a consequent decrease in its availability to organisms.     

Trace metals in mussels from mariculture zones, Hong Kong

In 1997, concentrations of cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb) and nickel (Ni) were analysed in green-lipped mussels (Perna viridis) from three mariculture zones located in the north-east (Kat O), south (Lo Tik Wan) and to the west (Ma Wan) of Hong Kong. Spatial differences in the concentration of metals were found, chromium and copper were higher at Ma Wan and Lo Tik Wan compared to Kat O in the north-east. In contrast, the highest levels of lead (mean = 4.37 microg/g dry wt) were recorded at Kat O. There were no differences in the level of nickel between the study sites. A comparison of the metal concentrations in mussels with the results of a previous study seven years before, in 1990, showed a twofold increase in the mean levels of cadmium for all three sites. However, levels of the other metals in 1997 were lower by 12-32% for chromium, 32-39% for copper and 24-25% for nickel. The greatest reductions were recorded for lead: Kat O (39%), Ma Wan (51%) and Lo Tik Wan (75%). This may be related to the introduction of lead-free petrol in 1991. Despite the apparent reduction in some heavy metal bioaccumulation between 1990 and 1997, from a public health risk perspective, the data suggest a continued need for monitoring of heavy metals in mussels from mariculture zones.     

Mercury species of sediment and fish in freshwater fish ponds around the Pearl River Delta, PR China: human health risk assessment

This study investigated total mercury (THg) and methylmercury (MeHg) concentrations in five species of freshwater fish and their associated fish pond sediments collected from 18 freshwater fish ponds around the Pearl River Delta (PRD). The concentrations of THg and MeHg in fish pond surface sediments were 33.1-386 ng g(-1) dry wt and 0.18-1.25 ng g(-1) dry wt, respectively. The age of ponds affected the surface sediment MeHg concentration. The vertical distribution of MeHg in sediment cores showed that MeHg concentrations decreased with increasing depth in the top 10 cm. In addition, a significant correlation was observed between %MeHg and DNA from Desulfovibrionacaea or Desulfobulbus (p<0.05) in sediment cores. Concentrations of THg and MeHg in fish muscles ranged from 7.43-76.7 to 5.93-76.1 ng g(-1) wet wt, respectively, with significant linear relationships (r=0.97, p<0.01, n=122) observed between THg and MeHg levels in fish. A significant correlation between THg concentrations in fish (herbivorous: r=0.71, p<0.05, n=7; carnivorous: r=0.77, p<0.05, n=11) and corresponding sediments was also obtained. Risk assessment indicated that the consumption of largemouth bass and mandarin fish would result in higher estimated daily intakes (EDIs) of MeHg than reference dose (RfD) for both adults and children.     

Ecological risk assessment of arsenic and metals in sediments of coastal areas of northern Bohai and Yellow Seas, China

Distributions of arsenic and metals in surface sediments collected from the coastal and estuarine areas of the northern Bohai and Yellow Seas, China, were investigated. An ecological risk assessment of arsenic and metals in the sediments was evaluated by three approaches: the Sediment Quality Guidelines (SQGs) of the United States Environmental Protection Agency (USEPA), the degree of contamination, and two sets of SQGs indices. Sediments from the estuaries of the Wuli and Yalu Rivers contained some of the greatest concentrations of arsenic, cadmium, copper, mercury, lead, and zinc. Median concentrations of cadmium and mean concentrations of lead and zinc were greater than background concentrations determined for the areas. All sediments were considered to be heavily polluted by arsenic, but moderately polluted by chromium, lead, and cadmium. Current concentrations of arsenic and metals are unlikely to be acutely toxic, but chronic exposures would be expected to cause adverse effects on benthic invertebrates at 31.4% of the sites.     

Atmospheric heavy metal deposition accumulated in rural forest soils of southern Scandinavia

Thirty-three years of measurements of atmospheric heavy metal (HM) deposition (bulk precipitation) in Denmark combined with European emission inventories form the basis for calculating a 50-year accumulated atmospheric input to a remote forest plantation on the island of Laesoe. Soil samples taken in two depths, 0-10cm and 10-20cm, at eight forest sites at the island were used to determine the increase in HM content in the eolian deposited top soils of the plantation. Concentrations of lead (Pb), cadmium (Cd), copper (Cu), zinc (Zn), vanadium (V), nickel (Ni) and arsenic (As) were determined in atmospheric deposition and in soils. The accumulated atmospheric deposition is of the same magnitude as the increase of these metals in the top soil.     

Organochlorine and mercury contamination in fish tissues from the River Nestos, Greece

Polychlorinated biphenyls (PCBs), hexachlorocyclohexane (HCH) isomers, dichlorodiphenyltrichloroethane (DDT) and its metabolites, other organochlorine pesticides such as hexachlorobenzene (HCB), chlordane compounds (CHLs, including trans-chlordane and cis- and trans-nonachlor) and the heavy metal mercury were quantified in muscle and liver of the European chub (Leuciscus cephalus, Linnaeus, 1758) and in the muscle of the barbel (Barbus cyclolepis, Heckel, 1837) at two sampling sites of the River Nestos, Greece. PCBs in muscle and DDTs in the liver tissues were the predominant organochlorinated contaminants. Among the PCBs, congeners 47 (up to 9.60 ng g(-1) wet wt.), 180 (up to 1.15 ng g(-1) wet wt.) and 190 (up to 1.50 ng g(-1) wet wt.) were the most frequent and abundant. The contamination degree by the sum of PCBs on the fish tissue samples from the River Nestos is lower or similar to PCB levels found in other ecosystems. Among the organochlorine pesticides, essentially only p,p'-DDD, p,p'-DDE and alpha-, beta- and gamma-HCH were found, with the former appearing at mean levels up to 30.71 ng g(-1) wet wt. From a public health standpoint, residue organochlorine pesticide levels from our work are considerably lower than the recommended tolerance limits. Finally, mean values of Hg in chub were significant lower (up to 31.04 ng g(-1) wet wt.) compared to those detected on barbel (up to 169.27 ng g(-1) wet wt.). The concentrations of Hg in fresh water fish from the River Nestos did not exceed WHO and US EPA health guidelines, and were suitable for human consumption.     

Heavy-metal pollution assessment in the coastal lagoons of Jacarepaguá, Rio de Janeiro, Brazil

The Jacarepaguá lagoon receives the waste from 239 industries and domestic sewage. Bottom sediment analysis revealed that metal pollution is not spread over the lagoons but restricted to the discharge areas of the main metal-carrier rivers. Metal concentrations in superficial water showed the following concentrations values in ng/ml: Zn, 9.63+/-3.59; Pb, 0.61+/-0.43; Cu, 0.94+/-0.45; Mn, 12.7+/-8.0. Metal concentration in fish (average of seven different species) presented the following results, in mg/kg wet weight: Cr, 0.08+/-0.01; Cu, 0.4+/-0.15; Zn, 4.6+/-3.4; Fe, 2.4+/-1.3; Mn, 0.4+/-0.3. These results imply, considering fish consumption rate and the RfD (USEPA Reference Dose), that the local population is not exposed to undue health risks. Metal concentrations in the water may, however, increase due to their dissolution induced by pH and redox changes in the sediments.     

Exposure to polybrominated diphenyl ethers associated with consumption of marine and freshwater fish in Hong Kong

Concentrations of polybrominated diphenyl ethers (PBDEs) in market fish have not previously been reported in Hong Kong. Axial and ventral muscles from 10 each common species of freshwater and marine fish purchased from markets in Hong Kong were analyzed for 22 PBDEs. Among the 10 freshwater fish species, spotted snakehead (Channa maculate) contained the highest level of PBDEs in ventral muscle (130 ng g(-1) wet wt.). For marine fish, bigeye (Priacanthus macracanthus) showed significantly higher levels of PBDEs (60.7 ng g(-1)wet wt. in ventral tissue) than all other marine species. The levels of PBDEs in fish samples ranged from 0.53 to 130 ng g(-1)wetwt. The tetrabrominated congener BDE-47 and pentabrominated BDE-99 were the predominant congeners, which accounted for 27% and 30%, respectively, of the total PBDEs. Daily PBDE intake was calculated according to the different fish consumption rate for Hong Kong consumers, and the results ranged from 222 to 1198 ng day(-1) for marine fish and 403-2170 ng day(-1) for freshwater fish. The daily PBDE intake from fish reported here were higher than those reported from the United States (8.94-15.7 ng day(-1)) and Europe (14-23.1 ng day(-1)).     

Comparison of heavy metal levels of farmed and escaped farmed rainbow trout and health risk assessment associated with their consumption

Environmental Science and Pollution Research - In this study, levels of ten metals (arsenic, cadmium, cobalt, chromium, copper, iron, manganese, nickel, lead, and zinc) in muscles of farmed and...     

Altered vegetative assemblage trajectories within an urban brownfield

Recognizing the growing importance of both structure (maintenance of biodiversity) and function (fostering natural cycles) of urban ecologies, we examine coarse scale (herbaceous, shrub and forest) beta guild trajectory in an urban brownfield. The distribution of the pioneer forest assemblage dominated by Betula populifolia Marsh. and Populus spp. could be correlated positively with total soil metal load (arsenic, cadmium, chromium, copper, lead, zinc, lead and vanadium),whereas herbaceous and shrub guilds were negatively correlated. Distinct assemblage development trajectories above and below a critical soil metal threshold are demonstrated. In addition, we postulate that the translocation of metals into the plant tissue of several dominant species may provide a positive feedback loop, maintaining relatively high concentrations of metals in the litter and soil. Therefore assembly theory, which allows for the development of alternate stable states, may provide a better model for the establishment of restoration objectives on degraded urban sites.     

Guidelines for routine mercury speciation analysis in seafood by gas chromatography coupled to a home-modified AFS detector. Application to the Andalusian coast (south Spain)

A home-modified atomic fluorescence detector (mAFS) has been employed for mercury and methylmercury determination in bivalves from the Andalusian coast (south Spain). This modification consists on the inclusion of a quartz flow cell into the detector, which increases the concentration of mercury atoms in the detector and therefore enhances sensitivity about two fold. Two analytical approaches for mercury speciation based on the coupling of gas chromatography on-line pyrolysis and mAFS (GC-Pyro-mAFS) have been tested. The first approach (Method 1) is based on aqueous ethylation followed by extraction into an organic solvent, and the second one (Method 2) in the extraction of monoalkylated mercury as chloride. Method 1 is a rapid procedure but not sensitive enough for the analysis of methylmercury in non-polluted sites (detection limit: 20 ng g(-1) as mercury, wet basis). The second one is quite more sensitive (detection limit: 0.2 ng g(-1), wet weight), but sample treatment is cumbersome and time-consuming. The optimum range for mercury determination for both methods are complementary and exhibit an overlapping measurable concentration range (OMCR) in which methylmercury can be indistinctly determined (75-100 ng g(-1) as mercury, wet basis). The suitability of both methods has been assayed with spiking experiences at levels within the OMCR with good recoveries. Both approaches have been validated with two certified reference materials (BCR-463, mercury and methylmercury in tuna fish; and NIST-2977, organic contaminants and trace metals in mussel tissue). Both procedures have been used for the analysis of three species of bivalve molluscs collected along the Andalusian coast (south Spain), all of them employed for human consumption (Chamelea gallina, Donax trunculus and Scrobicularia plana), and their potential use in routine analysis has been established.     

Metal contents of marine turtle eggs (Chelonia mydas; Lepidochelys olivacea) from the tropical eastern pacific and the implications for human health

Concentrations of eight elements were measured in Chelonia mydas and Lepidochelys olivacea eggs collected along the Pacific coast of Panama. Manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd), and mercury (Hg) concentrations were similar to previous reports of these species from around the world, while lead (Pb) was lower than previous reports. Cd posed the highest health risk to people who regularly eat the eggs, with average consumption rates leading to target hazard quotients (THQ) of up to 0.35 ± 0.15. Our conclusions indicate that current turtle egg consumption in isolated, coastal Pacific communities may pose a health concern for young children, and that youth and young adults should limit their consumption of turtle eggs to reduce their total intake of nonessential metals.     

A survey of mercury,lead and cadmium in muscle of British freshwater fish

Analyses of mercury, lead and cadmium in muscle of 221 fish, mainly eel and roach, from 67 sites in Great Britain are presented. Concentrations of metals in a significant number of fish were above recommended standards for human consumption.     

Effects of heavy metal exposure on the condition and health of nestlings of the great tit (Parus major), a small songbird species

In this study we examined the possible effects of heavy metal exposure on the condition and health of great tit nestlings (Parus major) at four study sites along a pollution gradient near a large non-ferrous smelter in Belgium during three consecutive breeding seasons. Our results showed that nestlings were indeed exposed to large amounts of heavy metals. Excrements contained significantly higher concentrations of several heavy metals (silver, arsenic, cadmium, mercury, lead) near the pollution source than at study sites farther away. When taking into account the number of young in the nest at the time of sampling, nestling body mass and condition were significantly reduced at the most polluted site. Nestlings at the two most polluted sites fledged significantly later than at the least polluted site. We also observed growth abnormalities of the legs near the pollution source. Tarsus length, wing length and haematocrit values did not differ significantly among study sites.