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Archives of Environmental Contamination and Toxicology (v.47, #2)
A Sonication Extraction Method for the Analysis of Pyrethroid, Organophosphate, and Organochlorine Pesticides from Sediment by Gas Chromatography with Electron-Capture Detection by J. You; D. P. Weston; M. J. Lydy (pp. 141-147).
A method was developed for the simultaneous determination of 5 pyrethroid, 1 organophosphate, and 20 organochlorine pesticides in sediment. Pesticide residues were extracted using sonication with acetone-methylene chloride (1:1 vol/vol) and the extracts were subsequently cleaned with deactivated Florisil (magnesium silicate; U.S. Silica, Berkeley Springs, West Virginia). Gas chromatography with an electroncapture detector was used for analyte determination, and two columns were used for confirmation of the analytes. Four control sediments from different sources were spiked with a pesticide mix and analyzed for method validation. The method detection limits ranged from 0.22 to 0.85 µg/kg dry sediment. Recoveries for spiked samples at four concentrations (1, 5, 20, and 400 µg/kg dry sediment) were 71.9% to 129.8% with relative standard deviations (RSDs) < 11%. Taking the matrix effect into account, 1 µg/kg was chosen for the threshold of detection, but 0.5 µg/kg of spiked control sediment still provided good recoveries and RSDs. This method was validated using field-collected sediment taken from agricultural areas of Fresno County, California.
Evaluation of Desulfuration Methods for Pyrethroid, Organophosphate, and Organochlorine Pesticides in Sediment with High Sulfur Content by J. You; M. J. Lydy (pp. 148-153).
This study investigated different cleanup procedures to eliminate sulfur interference from sediments from a reclaimed mining site in Sparta, Illinois. Sonication extraction with activated copper powder was the most effective method to eliminate elemental sulfur. Extracts were then cleaned with a Florisil column before pyrethroid, organophosphate, and organochlorine pesticides were determined using gas chromatography with electron-capture detection. The method detection limits ranged from 0.03 to 0.68 µg/kg dry sediment. Recoveries for spiked samples were from 82.2% to 132.7% with relative standard deviations < 15%. Fifty-four sediment samples collected from 15 lakes and 1 stream in the proposed Illinois National Guard Armory were analyzed using the desulfuration procedure. Of the 26 target pesticides analyzed in sediment, 20 were detected above the detection threshold of 1 µg/kg. DDT was detected most frequently (found at 50% of the sampling sites), whereas permethrin was found at the greatest concentration.
The Binary Treatment of Aqueous Metribuzin Using Anodic Fenton Treatment and Biodegradation by E. M. Scherer; Q.-Q. Wang; A. G. Hay; A. T. Lemley (pp. 154-161).
An advanced oxidation process, anodic Fenton treatment (AFT), and a mixed microbial culture were used to degrade metribuzin [4-amino-6-tert-butyl-3-methylthio-1,2,4- triazin-5(4H)-one], a broad-use triazinone herbicide. Complete and rapid removal of metribuzin was demonstrated. The appearance and subsequent degradation of metribuzin oxidation products—deaminated metribuzin (DA), diketo metribuzin (DK), as well as the production of deaminated diketo metribuzin (DADK)—were observed. To support the use of AFT as a chemical pretreatment, the ratio of 5-day biochemical oxygen demand (BOD5) as measured in the standard test to chemical oxygen demand (COD) was investigated, and an increase from 0.03, a nonbiodegradable solution, to 0.35, a biodegradable solution, was observed. This increase in biodegradability was associated with decreased metribuzin, DA, and DK concentrations and increased DADK concentration. AFT effluent was inoculated with either an enriched microbial culture or Polyseed, a commercially available inoculum. Although there was minimal biodegradation of the remaining metribuzin, there was a significant decrease in DA concentration in inoculated incubations compared with sterile controls after 5- and 10-minute AFT treatment. The enrichment inoculate appeared more adapted toward the less-oxidized, 5-minute–treated effluent, whereas the Polyseed culture, developed to degrade complex waste solutions, appeared to be more effective in a moreoxidized, 10-minute–treated, and potentially more complex effluent. This research supports the continued investigation of AFT and biodegradation as a binary treatment of aqueous pesticide wastes.
Heavy Metals in Airborne Particulate Matter of Urban Coimbatore by R. Mohanraj; P. A. Azeez; T. Priscilla (pp. 162-167).
Exposures to airborne metals are known to cause physiological responses in organisms and wide-ranging health effects in humans. Hence determination of metals in particulate matter is important from a toxicological perspective. In the current study heavy metals associated with respirable (RSPM) and nonrespirable (NRSPM) fractions of suspended particulate matter were estimated in air samples from six stations in Coimbatore, India, during March 1999 to February 2001. The mean quantity of heavy metals in RSPM was in the order Zn > Cu > Pb > Ni > Cr > Cd. Concentrations of these heavy metals were in the range of BDL (below detectable level) to 2147 ng/m3 in RSPM. The highest level of lead (2147 ng/m3) was recorded at an industrial station. The station also had the highest mean value (481 ± 544.3 ng/m3), suggesting the importance of industrial operations in determining the ambient concentrations of lead. Significant positive correlation among metals excepting lead and copper suggests that they originate mostly from a common source. Air samples of urban and industrial areas showed higher concentrations than residential (Urban) and suburban areas.
Degradation of Aromatic Hydrocarbons by Sphingomonas paucimobilis Strain EPA505 by S. P. Story; E. L. Kline; T. A. Hughes; M. B. Riley; S. S. Hayasaka (pp. 168-176).
To determine the substrate range capability of Sphingomonas paucimobilis strain EPA505, a number of aromatic compounds were tested as potential growth substrates. Strain EPA505 grew on phenanthrene, naphthalene, fluoranthene, toluene, benzoic acid, 2,3- and 3,4-dihydroxybenzoic acids, 1-chloro-2,4-dinitrobenzene, anthracene, 2-hydroxy-3-naphthoic acid and 1-hydroxy- 2-naphthoic acid, salicylic acid, and catechol. Strain EPA505 was unable to grow on coumarine 3-carboxylic acid, naphthalene dicarboxylic acid, acenaphthene, chrysene, pyrene, benzo[b]fluoranthene, and fluorene. Catabolic products were not detected or identified when the bacterium was incubated with coumarine 3-carboxylic acid, naphthalene dicarboxylic acid, acenaphthene, chrysene, or benzo[b]fluoranthene. Dihydroxypyrene, the ortho ring fission product of pyrene, and 10-hydroxy-1- phenanthroic acid were detected when the bacterium was incubated with pyrene. The open rings of benzo[b]fluoranthene, hydroxyacephenanthroic acid, hydroxyacephenanthrene, and phenanthrene anhydride, catabolites of benzo[b]fluoranthene degradation, were detected with Tn5 mutants of EPA505. With strain EPA505, both 9-fluorenone and an open ring fission product accumulated during incubation with fluorene. Other catabolites beyond the open ring of fluorene were detected, specifically dihydroxyfluorene, hydroxy-9-fluorenone, dihydroxy-9-fluorenone, hydroxyindane, and a putative glutathione-conjugated benzylanhydride. Benzylanhydride appeared to be a final end product of fluorene degradation by strain EPA505.
The Effect of Anthracene and Phenanthrene on the Growth, Photosynthesis, and SOD Activity of the Green Alga Scenedesmus armatus Depends on the PAR Irradiance and CO2 Level by A. Aksmann; Z. Tukaj (pp. 177-184).
Short-term (24-h) experiments were performed to examine the effect of phenanthrene (PHE) and anthracene (ANT) on algae grown in a batch culture system at irradiances of 12, 33, 48, and 64 W m–2 of the PAR range. Cultures were aerated (0.1 or 2% CO2) or nonaerated. As a result of aeration the concentration of ANT dropped from 0.45 mg L–1 at the beginning of the experiment (t0) to an undetectable value after 10 h. The PHE concentration dropped from 9.36 mg L–1 at t0 to 0.17 mg L–1 after 24 h. ANT at nominal concentrations exceeding 0.05 mg L–1 inhibited the growth of the algae in a concentration- and irradiance-dependent manner. The algistatic effect of ANT observed at 64 and 48 W m–2 was independent of the CO2 level, whereas the growth inhibition at 33 and 12 W m–2 was much greater in cultures aerated with 2% than with 0.1% CO2. PHE inhibited the growth only at a concentration of 10 mg L–1 (about 50% of the control) regardless of the irradiance or the CO2 concentration. The toxicity of both PHE and ANT was similar in aerated (0.1% CO2) and nonaerated cultures. ANT and PHE had a distinct effect on the photosynthesis. At 0.1% CO2, the irradiance-dependent inhibition (ANT) and stimulation (PHE) of the photosynthesis was observed. The inhibitory effect of ANT was enhanced when algae were grown at 2% CO2, but at the same CO2 concentration PHE did not affect the photosynthesis. ANT stimulated the total superoxide dismutase (SOD) activity in the cells, this effect being generally more pronounced at elevated CO2 levels and increasing with the irradiance. The total SOD activity was 250–300% higher in cells treated with PHE aerated with 0.1% CO2. At 2% CO2 no effect of PHE on the enzyme’s activity was noted. The results obtained indicate that ANT acts as a photosensitizer causing an oxidative damage of cells, while PHE seems to affect the macromolecular synthesis.
Responses of Antioxidative Enzymes to Accumulation of Copper in a Copper Hyperaccumulator of Commoelina communis by Haiou Wang; Xiao-quan Shan; Bei Wen; Shuzheng Zhang; Zi-jian Wang (pp. 185-192).
Discovery of a copper hyperaccumulator is very important for phytoremediation of copper-contaminated soil. In the present study a link was established between the copper accumulation in hyperaccumulator and that in nonaccumulator species of Commelina communis and its responses of antioxidative enzymes, including superoxide dismutase, guaiacol peroxidase, and ascorbate peroxidase. It was verified that copper exerted little physiological damage to copper hyperaccumulator species of Commelina communis at copper accumulation of >1000 µg/g in dry leaf tissue. However, in nonaccumulator species of Commelina communis superoxide dismutase, guaiacol peroxidase, and ascorbate peroxidase were activated, and malondialdehyde content was increased, which were symptoms of physiological damage by copper intoxication. Therefore, antioxidative enzymes can be used as an indicator of copper toxicity before the visible symptoms can be observed.
Teratogenic Versus Mutagenic Abnormalities in Chironomid Larvae Exposed to Zinc and Lead by Edward A. Martinez; Barry C. Moore; John Schaumloffel; Nairanjana Dasgupta (pp. 193-198).
Before chironomid mouthpart deformities can be utilized as indicators of aquatic metal pollution with certainty, it must first be established that deformities are teratogenic and not mutagenic. A laboratory experiment was conducted to assess this question using Zn and Pb as causative agents. Parent populations were reared in sediments spiked with zinc (Zn) or lead (Pb) and their resulting offspring (F1 generation) were reared in clean sediments. The proportions of mouthpart deformities in C. tentans larvae were compared via logistic regression, accounting for time of exposure, between parent and offspring populations. Results indicate that 14% of chironomids from Zn-spiked sediment contained deformed menta and/or mandibles. However, the F1-Zn generation displayed a deformity of 1.7%. Larvae reared in Pb-spiked sediments displayed a deformity frequency of 9% and the F1 generations (F1-Pb a and F1-Pb b) had deformity proportion of 7 and 6%, respectively. We concluded that the deformities caused by Zn stress were morphological because the resulting F1 deformity frequencies declined to control levels. However, deformities caused by Pb appear to be genetic since F1 deformity percentages did not differ from the parent deformity frequency. Because larvae reared in Zn- and Pb-spiked sediments were larger than larvae reared in uncontaminated sediments, we could not conclude that Zn and Pb in the sediments stunted the development of C. tentans.
Toxicity of Parking Lot Runoff After Application of Simulated Rainfall by D. Greenstein; L. Tiefenthaler; S. Bay (pp. 199-206).
Stormwater runoff is an important source of toxic substances to the marine environment, but the effects of antecedent dry period, rainfall intensity, and duration on the toxicity of runoff are not well understood. In this study, simulated rainfall was applied to parking lots to examine the toxicity of runoff while controlling for antecedent period, intensity, and duration of rainfall. Parking areas were divided into high and low use and maintained and unmaintained treatments. The parking stalls were cleaned by pressure washing at time zero. Simulated rainfall was then applied to subplots of the parking lots so that antecedent periods of 1, 2, and 3 months were achieved, and all of the runoff was collected for analysis. On a separate parking lot, rainfall was applied at a variety of intensities and durations after a 3-month antecedent period. Runoff samples were tested for toxicity using the purple sea urchin fertilization test. Every runoff sample tested was found to be toxic. Mean toxicity for the sea urchin fertilization test ranged from 2.0 to 12.1 acute toxic units. The toxicity increased rapidly during the first month but then decreased approximately to precleaning levels and remained there. No difference in toxicity was found between the different levels of use or maintenance treatments. The intensity and duration of rainfall were inversely related to degree of toxicity. For all intensities tested, toxicity was always greatest in the first sampling time interval. Dissolved zinc was most likely the primary cause of toxicity based on toxicant characterization of selected runoff samples.
Relative Importance of Ingested Sediment Versus Pore Water as Uptake Routes for PAHs to the Deposit-Feeding Oligochaete Ilyodrilus templetoni by Xiaoxia Lu; Danny D. Reible; John W. Fleeger (pp. 207-214).
The relative role of sediment pore water and ingested sediment particles to the total uptake of sediment-associated hydrophobic organic contaminants was examined by estimation from a water-only exposure experiment and from a bioenergetic-based toxicokinetic model utilizing experimentally measured sediment ingestion rates, assimilation efficiencies, and elimination rates. Phenanthrene (PHE) and benzo[a]pyrene (BaP) uptake in the bulk deposit-feeding oligochaete, Ilyodrilus templetoni, was measured. Assimilation efficiencies (ASE) were measured using a pulse-chase technique, based on a single-gut-passage time. Sediment-associated phenanthrene exhibited a lower ASE (50%) compared to BaP (80%), possibly due to a general relationship between assimilation and compound logK ow. Estimated uptake of phenanthrene from pore water alone was essentially equal to the observed total uptake from both ingested sediment and sediment pore water. Estimated contribution of sediment-bound phenanthrene accounted for less than 20% of the total uptake. For benzo[a]pyrene, estimated uptake from sediment ingestion accounted for essentially all of the total uptake and estimated absorption from pore water accounted for <5% of the total uptake. This research provides direct experimental evidence for a predicted increase in the importance of sediment ingestion relative to the pore water route of exposure as the hydrophobicity of organic contaminants increases.
Toxicity, Uptake, and Release of the Water-Soluble Fraction of Crude Oil in Different Developing Stages of the Prawn Macrobrachium borellii by S. Lavarías; H. Heras; R. J. Pollero (pp. 215-222).
The effects of a water-soluble fraction of light crude oil dissolved in freshwater (WSF) on Macrobrachium borellii exposed at three life stages was evaluated. Adults, larvae (PL), and embryos were exposed to five levels of WSF for 96 h. At 48 and 72 h PL were significantly more sensitive to WSF than adults, though values for 96-h LC50 were not significantly different (1.56 and 1.41 mg/L, respectively). Mortality was never high enough to allow LC50 calculation in embryos, but chronic exposure to WSF increased the mortality near hatching and significantly decreased PL survival compared to the control group. The uptake, accumulation, and depuration of WSF were evaluated in adult prawns (lipid content 1.5% wet wt) exposed to a sublethal concentration for 96 h followed by a 10-d depuration period. Hydrocarbons were rapidly taken up, and after 24 h most of them reached an equilibrium concentration. Increases in the number and alkylation of the aromatic rings enhanced both their accumulation and their retention. When returned to clean freshwater, levels of lighter aromatics dropped rapidly over 12 h. From these studies we conclude that early life stages of M. borellii are not very vulnerable to WSF toxicity, while adults have a rapid uptake and release of most of the contaminating hydrocarbons, probably due to their low lipid levels.
Bioaccumulation of Arsenic in Marine Fish and Invertebrates from Alaska and California by James P. Meador; Don W. Ernest; Anna Kagley (pp. 223-233).
Past studies determined that concentrations of arsenic in the liver of flathead sole from Alaska were generally higher than those found in fish from other locations sampled along the west coast of the United States (Meador et al. 1994). A study was conducted to examine arsenic concentrations and patterns of bioaccumulation in fish and potential prey species from two geographic locations. Flathead sole were collected from four sites in the Gulf of Alaska and white croaker and English sole were collected from five sites in California. Potential prey species from each site were also examined and found to contain high concentrations of arsenic. In California, the sites with the lowest sediment concentrations of arsenic, total organic carbon, and acid-volatile sulfides (AVS) contained invertebrates with the highest tissue concentrations. Regression analysis determined that arsenic in polychaetes was highly correlated to sediment concentrations of arsenic normalized to AVS but was higher overall for the California samples. Even though invertebrates from several of the California sites exhibited much higher concentrations of arsenic than invertebrates from the Alaska sites, liver and muscle tissue from flathead sole collected in Alaska usually exhibited higher concentrations than fish from the California sites. When concentrations of arsenic in fish liver were plotted against concentrations of arsenic in sediment normalized to AVS levels, a very high correlation was obtained for all sites. This suggests that AVS, or some factor correlated with AVS, may have been responsible for controlling arsenic bioaccumulation in these fish species through dietary uptake and exposure to arsenic in water. Based on the available data, it appears that dietary uptake may be related to fish tissue concentrations, but uptake of aqueous arsenic may be responsible for the higher tissue concentrations in fish from Alaska.
Impact of Ammonium Nitrate on Growth and Survival of Six European Amphibians by Manuel E. Ortiz; Adolfo Marco; Nelia Saiz; Miguel Lizana (pp. 234-239).
We conducted static experiments to assess the effects of ammonium nitrate fertilizer on embryos and larvae of six European amphibians: sharp-ribbed salamander (Pleurodeles waltl), Iberian painted frog (Discoglossus galganoi), western spadefoot toad (Pelobates cultripes), common toad (Bufo bufo), natterjack toad (Bufo calamita), and common tree frog (Hyla arborea). Embryos were exposed to different and environmentally relevant concentrations of ammonium nitrate (0 to 200 mg NO3 −/L) for 15 days. Hatching took place during the experiments. H. arborea was extremely sensitive and had high mortality after 8 days of exposure even at the lower fertilizer levels. D. galganoi and B. bufo were also very sensitive and had significant mortality after 15 days of exposure. The rest of the species did not suffer lethal effects but suffered abnormalities or decreased growth at the highest fertilizer concentrations. Chemical fertilizers or manure could have contributed to the observed decrease of B. bufo and D. galganoi in agricultural areas of the Iberian Peninsula during recent years. H. arborea was the most sensitive species studied. The results of our study showed that environmentally relevant levels of ammonium nitrate can induce mortality and might affect population dynamics of this species in agricultural environments.
Contaminant Residues in Snapping Turtle (Chelydra s. serpentina) Eggs from the Great Lakes–St. Lawrence River Basin (1999 to 2000) by S. L. Ashpole; C. A. Bishop; R. J. Brooks (pp. 240-252).
To determine temporal and geographic variations of environmentally persistent pollutants, the concentrations of several contaminants were measured in snapping turtle eggs in 1999 and 2000. Contaminants included polychlorinated biphenyls (PCBs), non-ortho PCBs, polychlorinated dibenzodioxins and furans, organochlorine pesticides, and total mercury. Egg collection sites within the St. Lawrence Area of Concern (AOC) and the Territory of Akwesasne included Turtle Creek, Snye Marsh, and Raquette River. Additional contaminated sites were Gray’s Creek (within the St. Lawrence AOC boundary), Coote’s Paradise (Hamilton Harbour AOC), and the Territory of Walpole Island (St. Clair AOC). Reference sites were Lake Sasajewun, Algonquin Provincial Park in central Ontario, and in close proximity to the St. Lawrence Area AOC, Hoasic Creek and Cooper Marsh. Eggs from clutches collected from Akwesasne contained the highest concentrations of contaminants. Mean total PCB concentrations for Akwesasne clutches ranged from 1,900 to 61,000 ng/g wet weight (w.w.), which was 360 to 3,100 times higher than the mean concentrations at the reference sites. The high levels of contaminants in eggs, from sites within Akwesasne, were consistent with trends reported in the past and reflect the influence of the proximity of heavy industry. Current contaminant concentrations in clutches from Coote’s Paradise are comparable with those recorded in 1989 and 1990 but are 200 to 800 times lower than concentrations reported in 1984 and 1988. Eggs from Lake Sasajewun contained relatively low contaminant levels, which is consistent with atmospheric deposition. Our results support that snapping turtles are good indicators of temporal and geographic contaminant trends.
The Effect of Sex on Avian Plasma Cholinesterase Enzyme Activity: A Potential Source of Variation in an Avian Biomarker Endpoint by Jonathan D. Maul; Jerry L. Farris (pp. 253-258).
Accurate identification of contaminant exposure to nontarget organisms involves understanding sources of variation associated with contaminant specific biomarkers. Cholinesterase (ChE) enzyme activity is the biochemical endpoint most often used to assess organism exposure to organophosphorus (OP) pesticides. A potential source of variation for this biomarker is sex, however, a generalized pattern of sex as a source of variation for avian ChE levels remains equivocal. In this study, sex-dependent variation in plasma ChE activity was examined in breeding northern cardinals (Cardinalis cardinalis) from reference populations free of OP pesticide exposure. Male (n = 32) total ChE activity (1.745 ± 0.541) was greater than female (n = 26) total ChE activity (1.480 ± 0.576) (p = 0.015). Likewise, benchmarks based on reference means and used for exposure identification (e.g., 20% reduction and the diagnostic threshold) were higher in males than females. With females having a 15.2% lower ChE activity than males, a substantial source of error exists for exposure assessment since some researchers consider a 20% inhibition as evidence of exposure. A second objective was to survey published literature to examine the extent that studies have accounted or controlled for the potential effect of sex on ChE activity. More studies (56.3%) pooled data for male and female ChE activity than studies that statistically tested for an effect (20.3%) or tested hypotheses using a single sex (23.4%) (p < 0.0001; n = 64). Based on these findings, it is suggested that the effect of sex be considered in future studies using the ChE biomarker for identification of passerine exposure to OP pesticides, particularly if examining plasma sources of ChE in actively breeding passerines.
Comparative Tissue Distribution of Metals in Birds in Sweden Using ICP-MS and Laser Ablation ICP-MS by Kristine H. Ek; Gregory M. Morrison; Peter Lindberg; Sébastien Rauch (pp. 259-269).
Cadmium, copper, lead, palladium, platinum, rhodium, and zinc profiles were investigated along feather shafts of raptor and other bird species by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The distribution of external versus internal metal contamination of feathers was investigated. The species examined were peregrine falcon (Falco peregrinus), sparrowhawk (Accipiter nisus), willow grouse (Lagopus lagopus), and house sparrow (Passer domesticus) in Sweden. For habitat comparisons, total Cu, Pb, Zn, and Cd concentrations were analyzed by ICP-MS in feathers of the examined species as well as captive peregrine falcon. For investigation of metal distribution and correlation in different biological materials of raptors, total concentrations of Cu, Pb, Cd, and Zn were also investigated by ICP-MS in feathers, eggs, blood, feces, liver, and kidney of wild peregrine falcon from southwestern Sweden.Laser ablation of feathers revealed that Pb contamination is both external and internal, Zn contamination is internal, and Cd and Cu contamination is predominantly internal, with a few externally attached particles of high concentration. Pb, Cu, and Cd signal intensities were highest in urban habitats and contamination was mainly external in feathers. The background signal intensity of Zn was also higher in birds from urban habitats. The laser ablation profile of PGE (Pt, Pd, Rh) demonstrated that PGE contamination of feathers consists almost exclusively of externally attached PGE-containing particles, with little evidence of internally deposited PGE.Generally, total metal concentrations in feathers were highest in sparrowhawk and house sparrow due to their urban habitat. Total Cu, Zn, and Cd concentrations were highest in liver and kidney due to binding to metallothionein, while the total Pb concentration was highest in feces due to the high excretion rate of Pb. A decreasing temporal trend for Pb in feathers, showing that Pb levels in feathers have decreased since the introduction of nonleaded petrol, is also discussed.
Lead in Feathers and δ-Aminolevulinic Acid Dehydratase Activity in Three Raptor Species from an Unpolluted Mediterranean Forest (Southeastern Spain) by E. Martínez-López; J. E. Martínez; P. María-Mojica; J. Peñalver; M. Pulido; J. F. Calvo; A. J. García-Fernández (pp. 270-275).
This paper presents the levels of lead found in the feathers of adult and blood of nestlings of booted eagle (Hieraaetus pennatus), European buzzard (Buteo buteo), and goshawk (Accipiter gentilis) sampled in the 1999 and 2000 breeding seasons in a Mediterranean forest of the Province of Murcia (Southeastern Spain) located far from potential sources of metal contamination. Levels of δ-aminolevulinic acid dehydratase activity (δ-ALAD) in blood were also measured in the nestlings. Lead concentrations ranged from 1.1 to 11.21 μg/dl in blood of nestlings and from 0.35 to 1.66 mg/kg d.w. in the feathers of their parents. A significant relationship was found between blood δ-ALAD and lead (ρ = −568), showing a negative correlation with blood lead levels even at lead concentrations below 5 μg/dl. This fact suggests the usefulness of this enzymatic biomarker for low lead exposure in forest raptors. There were also positive relationships between the lead concentrations in blood of nestlings and those in feathers of their parents (ρ = 0.817), suggesting the usefulness of feathers for biomonitoring environmental exposure to lead.
Association Between Aminolevulinate Dehydrase Genotypes and Blood Lead Levels in Children from a Lead-Contaminated Area in Antofagasta, Chile by F. Pérez-Bravo; M. Ruz; M. J. Morán-Jiménez; M. Olivares; A. Rebolledo; J. Codoceo; V. Sepúlveda; A. Jenkin; J. L. Santos; A. Fontanellas (pp. 276-280).
Childhood environmental lead exposure in the city of Antofagasta, Chile, was generated by the accumulation of recently removed lead stores derived from mining activities for a long period of time. Susceptibility to harmful lead effects may be associated with polymorphisms of delta-aminolevulinic acid dehydratase (ALAD) because of the differential binding of lead to the codified proteins. We assessed the associations and possible interactions among the following variables: blood lead levels, ALAD genotypes, and distance to the source of lead contamination in Chilean children exposed to lead contamination in Antofagasta, Chile. Ninety-three children were recruited from schools located near a lead- contaminated area. Lead blood levels were measured by atomic absorption spectrophotometry. ALAD genotypes were determined by polymerase chain reaction and restriction fragment-length polymorphism analysis. The frequency of the ALAD-2 allele was estimated at 0.054. Children with the ALAD-2 genotype had higher blood lead levels than noncarriers (p = 0.06). As expected, blood lead levels were inversely correlated with the distance from lead stores. Interestingly, ALAD-2 carriers were more frequent within the area defined by a distance of 200 m from lead deposits (27%) than in areas >200 m (5%) away. Children living within a maximum distance of 200 m from the lead stores showed higher blood lead levels in ALAD-2 carriers (geometric mean = 16.4 μg/dl, range 6 to 27) than in noncarriers (geometric mean = 12.1 μg/dl, range 0 to 26) without achieving statistical significance (p = 0.13). A trend for higher blood lead levels in ALAD-2 carriers compared with ALAD-1 homozygous children has been observed. Because ALAD-2 frequency was higher in subjects living within 200 m from the lead deposits, we hypothesized that a long-term selective pressure against the presence of the ALAD-1 allele is the cause of the overrepresentation of the ALAD-2 allele in children living in proximity to the recently removed lead stores.