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Archives of Environmental Contamination and Toxicology (v.40, #4)
Sorption of the Neutral and Charged Forms of Pentachlorophenol on Soil: Evidence for Different Mechanisms by J. P. DiVincenzo; D. L. Sparks (pp. 445-450).
Laboratory soil sorption experiments have been conducted on pentachlorophenol (PCP) at different pH values in an attempt to elucidate differences in sorption mechanisms between the charged and neutral species. Sorption of PCP on soil was investigated by maintaining pH 4 or 8 in batch sorption experiments. Pre-equilibration of the soil was necessary to maintain a constant pH over the course of the experiments. Additionally, a CaCO3-CO2/N2 buffered solution was necessary to maintain a pH of 8. Sorption of the neutral PCP species conformed to a linear isotherm model, while a Langmuir model provided the best fit for the charged species. Desorption of the neutral form was completely reversible over the sorption times studied but the charged species exhibited some resistance to desorption. Temperature effects on the distribution coefficients (Kd) were investigated and thermodynamic parameters were calculated. The ionized species showed a clear decrease in Kd with increasing temperature while the protonated species showed no apparent trend. Enthalpies (ΔH°), entropies (ΔS°), and free energies (ΔG°), support the conclusions that the neutral form of PCP partitions by hydrophobically binding to the soil while the charged form sorbs by a more specific exothermic adsorption reaction.
Inhibition of Aerobic Growth and Nitrification of Bacteria in Sewage Sludge by Antibacterial Agents by B. Halling-Sørensen (pp. 451-460).
Toxicity of antibacterial agents on environmentally relevant bacteria was investigated using activated sludge. The growth and nitrifying inhibiting effects for activated sludge of benzyl penicillin (penicillin G) (BP), tetracycline (TC), chlortetracycline (CTC), oxytetracycline (OTC), olaquindox (O), streptomycin (ST), tiamulin (TI), tylosin (TYL) sulfadiazine (SDZ), metronidazole (MET), and oxolinic acid (OXA) was investigated. Studies were performed in accordance to the ISO 15522 (1999) and ISO 9509 (1989) test guidelines, respectively. The toxicity (EC50 value, mg/L) found with the ISO 15522 was in decreasing EC50 values; O (95.7), BP (84.6), TYL (54.7), TI (14.3), TC (2.2), OTC (1.2), ST (0.47), CTC (0.40), and OXA (0.1). No observed effect concentrations (NOECs) (mg/L) of 100 and 60, respectively was found for MET and SDZ. Triplicate tests assessing the effects of the antibacterial agents on the nitrification rate gave indications only as the level of increased or decreased rate. More accurate data for the inhibition of Nitrosomonas europaea was found with a suspended culture of the nitrifying bacteria. The toxicity (EC50 value, mg/L) found was in decreasing EC50 values; TI (23.3), SDZ (17.0), TC (4.0), OTC (1.7), OXA (1.0), CTC (0.64), O (0.03), ST (0.02). For MET and TYL, NOECs (mg/L) of 100 and 50 were found, respectively. The antibacterial agents were also assessed using a pour plate method with both (separately tested) activated sludge bacteria and N. europeae showing to be 5 to 10 times more potent to most agents except SDZ, TI, and MET.
Evaluation of Contamination, by Different Elements, in Terrestrial Mosses by J. A. Fernández; A. Carballeira (pp. 461-468).
Evaluation was made of the degree to which samples of terrestrial mosses (Scleropodium purum and Hypnum cupressiforme) collected in Galicia (NW Spain) were contaminated by different elements. The concentrations of Al, As, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, Pb, S, Se, and Zn in the mosses were determined, then the contamination factors were calculated by dividing each value by the corresponding background level of that element. To assess contamination using contamination factors (CFs), a scale was established that allowed categorization of sampling sites for each element determined. The proposed scale comprises six categories, ranging from CF values of less than 1 (no contamination) to values of greater than 27 (extreme contamination). Finally, all available information was brought together and summarized in a contamination index. This index has the advantage that it takes into account the toxicity of the elements and that can be used with an already existing scale of classification.
Development of an Improved Rapid Enzyme Inhibition Bioassay with Marine and Freshwater Microalgae Using Flow Cytometry by N. M. Franklin; M. S. Adams; J. L. Stauber; R. P. Lim (pp. 469-480).
A rapid toxicity test based on inhibition of esterase activity in marine and freshwater microalgae (Selenastrum capricornutum, Chlorella sp., Dunaliella tertiolecta, Phaeodactylum tricornutum, Tetraselmis sp., Entomoneis cf. punctulata, Nitzschia cf. paleacea) was developed using flow cytometry. Uptake of fluorescein diacetate (FDA) was optimized for each species by varying the substrate concentration, incubation time, and media pH. Propidium iodide (PI) was utilized to assess membrane integrity. The optimized FDA/PI staining procedure was then used to assess the toxicity of copper in short-term exposures (1–24 h). Esterase activity was a sensitive indicator of copper toxicity in S. capricornutum and E. cf. punctulata. As copper concentrations increased, esterase activity decreased in a concentration-dependent manner. The 3- and 24-h EC50 values (based on mean activity states) were 112 μg Cu L−1 (95% confidence limits 88–143) and 51 μg Cu L−1 (95% confidence limits 38–70) for S. capricornutum and 47 μg Cu L−1 (95% confidence limits 43–51) and 9.1 μg Cu L−1 (95% confidence limits 7.6–11) for E. cf. punctulata, respectively. This enzyme inhibition endpoint showed similar sensitivity to chronic growth rate inhibition in E. cf. punctulata (48-h and 72-h EC50 values of 17 and 18 μg L−1, respectively) but was less sensitive compared to growth for S. capricornutum (48-h and 72-h EC50 values of 4.9 and 7.5 μg L−1, respectively). For the other five species tested, inhibition of FDA fluorescence was relatively insensitive to copper, even at copper concentrations that severely inhibited cell division rate. These short-term bioassays that detect sublethal endpoints may provide a more rapid and cost-effective way of monitoring contaminant impacts in natural waters.
Acute and Chronic Effects of Particle-Associated Fenvalerate on Stream Macroinvertebrates: A Runoff Simulation Study Using Outdoor Microcosms by R. Schulz; M. Liess (pp. 481-488).
Agricultural edge-of-field runoff usually contaminates surface waters with particle-associated pesticides. However, the acute and chronic effects on the aquatic macroinvertebrate communities have rarely been addressed. Outdoor flow-through stream microcosms were exposed for 1 h in triplicate to approximately 3.1 g/L of total suspended solids spiked with 0.0, 13.6, 136, or 1,365 μg/kg of the pyrethroid insecticide fenvalerate (FV). The effects on eight species typical of agricultural streams were monitored for 93 days. Gammarus pulex (Amphipoda) and Hydropsyche angustipennis (Trichoptera) showed a sensitive acute drift reaction with increased drift levels in all FV treatments (p < 0.05). The caddisfly species Anabolia nervosa, Plectrocnemia conspersa, and Limnephilus lunatus as well as the dipteran species Tipula maxima were less sensitive, with a significant increase in drift in the 136- and 1,365-μg/kg treatments. Temporal pattern of emergence was significantly altered in the 1,365-μg/kg treatment for A. nervosa (p < 0.05). The most sensitive species in terms of total emergence or survival were L. lunatus, which showed a significant effect in the 136- and 1,365-μg/kg treatment, as well as adult and juvenile G. pulex and T. maxima, with a significant effect level in the 1,365-μg/kg treatment (p < 0.05). Total emergence or survival of A. nervosa, P. conspersa, and H. angustipennis decreased with increasing exposure level, but differences from the control were not significant. Neither acute drift nor chronic mortality was observed for Helodes minuta (Coleoptera) and Radix peregra (Gastropoda). This study highlights the ecotoxicological importance and bioavailability of field-relevant levels of particle-associated hydrophobic chemicals transiently introduced into surface waters during runoff events.
A 48-h Larval Development Toxicity Test Using the Marine Polychaete Galeolaria caespitosa Lamarck (Fam. Serpulidae) by K. E. Ross; J. R. Bidwell (pp. 489-496).
Assessing the risk of effluents and other anthropogenic inputs to the receiving environment is ultimately best done on a site-specific basis, which often requires toxicity tests using organisms relevant to that environment. Additionally, the test species or life stage needs to be available for a reasonable portion of the year to allow temporal fluctuations to be assessed. A 48-h larval development toxicity test using the marine polychaete Galeolaria caespitosa was developed. This test was developed as G. caespitosa releases viable gametes year-round, and the test species is environmentally relevant to the marine system receiving the liquid effluent being evaluated. Toxicity tests were conducted using G. caespitosa from different locations and evaluating the gamete response to copper. All population responses were comparable, with EC50 values ranging from 16 to 40 μg/L copper (as CuCl2· 2H2O). Toxicity tests were also conducted using G. caespitosa gametes with an effluent produced by a lead smelting operation. The response of the G. caespitosa test with this effluent was compared with three other test methods using two microalgal species, Isochrysis sp. and Nitzschia closterium, and gametes from the mussel Mytilus edulis. The G. caespitosa larval development toxicity test was the most sensitive test to the effluent, with EC50 values ranging from 1–23% effluent, while it ranked second in sensitivity to copper. This test could be applied to other common serpulids worldwide.
The Influence of Suspended Particles on the Acute Toxicity of 2-Chloro-4-Nitro-Aniline, Cadmium, and Pentachlorophenol on the Valve Movement Response of the Zebra Mussel (Dreissena polymorpha) by J. Borcherding; J. Wolf (pp. 497-504).
The Dreissena-Monitor is a biological early warning system for the continuous monitoring of river water quality, based on the valve movements of two groups of 42 zebra mussels (Dreissena polymorpha). Laboratory experiments with Cd, PCP, and 2-chloro-4-nitro-aniline were conducted in combination with suspended particles (a mixture of stinging nettle powder, bentonite, and quartz powder). An increase of suspended particles up to a nominal concentration of 540 mg/L within 5 min did not evoke any reactions by the mussels significantly different from normal. The distribution between water and solids was analyzed for Cd and 2-chloro-4-nitro-aniline, with the result that the former quickly adsorbed to the particles, whereas the latter did not bind to the particles at all. The behavior of the zebra mussels revealed that the detection of 2-chloro-4-nitro-aniline was not affected by the presence of suspended matter. In the cases of Cd and PCP, D. polymorpha was able to detect these substances when they were particle-associated at least as well or better as when they were dissolved in the water. The results are discussed with respect to the physiology of the organisms and the bioavailability of toxicants, as well as to the consequences these results may have under field conditions.
Survival and Molting of the Pea Crab Larvae Tunicotheres moseri Rathbun 1918 (Brachyura, Pinnotheridae) Exposed to Copper by L. S. López Greco; J. Bolaños; E. M. Rodríguez; G. Hernández (pp. 505-510).
The acute lethal toxicity of copper, as well as its sublethal effect on molting, was studied on larval and postlarval stages of the pinnotherid crab Tunicotheres moseri. The most sensitive stage was zoea I, presenting a significant mortality above 0.5 μg · L−1. Abnormal setation of the maxillipeds was observed in zoeae II moulted from zoeae I exposed to 100 μg · L−1 and higher copper concentrations, causing a reduced swimming activity of the larvae. This pathology could be reverted after molting of affected zoea II to megalopa, which would be the first report in crustacean larvae that states the possibility of reverting morphological abnormalities after molting. For zoeae II and megalopae, the inhibition of molting and high mortality was registered at 1,000 μg · L−1. The effect of copper on the duration of the larval and postlarval stages was differential: It retarded the duration of the stage zoea I, did not modify that of zoea II, and accelerated the ecdysis of the megalopae to first crab. However, precocious molting to megalopae was associated with a smaller body size at the concentration of 100 μg · L−1. This differential effect of copper on the larval stages throughout the larval development could be ecologically relevant. Because of their lecithotrophia, their short developmental period, their good survival in control conditions, and the high sensitivity showed to copper (especially zoea I), larvae of T. moseri have shown that they are an excellent model for studying the effect of pollutant on survival, molting rate, growth, and morphogenetic changes during development.
Stored Retinoids in Populations of the Estuarine Fish Fundulus heteroclitus Indigenous to PCB-Contaminated and Reference Sites by D. Nacci; S. Jayaraman; J. Specker (pp. 511-518).
Concentrations of retinoids, derivatives of vitamin A, were measured in populations of the nonmigratory estuarine fish Fundulus heteroclitus, indigenous to a reference site and a site highly contaminated with polychlorinated biphenyls (PCBs) to address the hypothesis that contaminant exposure causes depletion of stored retinoids in native fish populations. To assess differences related to chemical exposure, as well as season and diet, hepatic retinoid analyses were conducted using fish collected early and late in the natural spawning season and after laboratory holding. Though hepatic retinoid composition was generally similar among groups, hepatic retinoid concentrations differed. Laboratory-held fish had higher hepatic retinyl ester concentrations than field-collected fish. Among field-collected fish, those collected early in the spawning season had higher hepatic retinyl ester concentrations than those collected later in the spawning season. Although there was no evidence of the dramatic retinoid depletions that have been reported in highly exposed populations of other fish species, hepatic retinoid stores were consistently lower in F. heteroclitus indigenous to the highly PCB-contaminated site. These results are consistent with prior findings that fish from this contaminated site are relatively insensitive to some of the toxic effects of PCB exposures, including retinoid depletion.
Bioaccumulation of Selected PCBs in Zebrafish, Three-Spined Stickleback, and Arctic Char After Three Different Routes of Exposure by P. L. Andersson; A. H. Berg; R. Bjerselius; L. Norrgren; H. Olsén; P.-E. Olsson; S. Örn; M. Tysklind (pp. 519-530).
The uptake and elimination of 20 structurally diverse tetra- to heptachlorinated biphenyls were studied in zebrafish (Danio rerio), three-spined stickleback (Gasterosteus aculeatus), and Arctic char (Salvelinus alpinus). The polychlorinated biphenyls (PCBs) were administered to the fish through food, intraperitoneal injection of peanut oil, or intraperitoneal implantation of silicone capsules. The retention of the PCBs in fish exposed through their diet was related with the substitution patterns of the compounds. Ortho-substituted congeners with no unsubstituted meta-para positions had high biomagnification potential. PCBs with low biomagnification all had adjacent vicinal hydrogens, indicating that congeners with this feature may have been metabolically eliminated. The retention characteristics of the PCBs in the diet-exposed and the injected zebrafish were similar. The pattern of congeners in Arctic char indicates that they have a lower capacity to metabolize PCBs compared to three-spined sticklebacks and zebrafish. The levels in the fish exposed to the PCBs through a silastic implant were negatively correlated with the hydrophobicity of the congeners. Most probably congener-specific release rates of the PCBs from the implants mask their retention characteristics. It is suggested that food, mimicking the natural intake route, should be used in PCB exposure studies to validate extrapolations to natural situations.
Accumulation and Selective Maternal Transfer of Contaminants in the Turtle Trachemys scripta Associated with Coal Ash Deposition by R. D. Nagle; C. L. Rowe; J. D. Congdon (pp. 531-536).
Coal combustion wastes are enriched in a number of potentially toxic compounds and may pose risks to biota exposed to the wastes. Slider turtles (Trachemys scripta) are common inhabitants of coal ash settling basins in South Carolina, USA, where they feed on contaminated prey items and accumulate high levels of potentially toxic compounds in their tissues. Furthermore, female sliders sometimes nest in contaminated spill piles and thus may expose embryos to contaminated soils. We examined two potential pathways by which female T. scripta may influence the survivorship and quality of their offspring in a contaminated habitat: (1) nesting in contaminated soil and (2) maternal transfer of pollutants. Eggs were collected from turtles captured in coal ash–polluted or unpolluted sites; individual clutches were incubated in both ash-contaminated and uncontaminated soil in outdoor, artificial nests. Incubation in contaminated soil was associated with reduced embryo survivorship. Adult females from the polluted site accumulated high levels of As, Cd, Cr, and Se in their tissues, yet Se was the only element transferred maternally to hatchlings at relatively high levels. Hatchlings from polluted-site females exhibited reduced O2 consumption rates compared to hatchlings from reference sites. Relatively high levels of Se transferred to hatchlings by females at the ash-polluted site might contribute to the observed differences in hatchling physiology.
DDT and the Decline of Free-Tailed Bats (Tadarida brasiliensis) at Carlsbad Cavern, New Mexico by D. R. Clark Jr. (pp. 537-543).
DDT is believed to have caused the population of Brazilian free-tailed bats (Tadarida brasiliensis mexicana) at Carlsbad Cavern to decline severely after 1936. Nevertheless, previous data supporting this hypothesis are limited to a single study from 1974, which indicated that 20% of young free-tails from the cavern may have died of DDE poisoning during their first southward migration. In this study I compared organochlorine residues among samples of free-tails collected in Carlsbad Cavern in 1930, 1956, 1965, 1973, and 1988. Samples of skin cut from dry museum specimens were chemically analyzed, except for the 1973 data, which were derived from analyses of whole bats minus gastrointestinal tracts. Accumulated residue levels of DDT compounds in bats from 1965 and 1956 exceeded those in 1973 bats by ≈ 4.8 times and ≈ 2.7 times, respectively. This suggests that lethal effects of DDT compounds were substantially greater in the 1950s and 1960s than in the 1970s. Residues in 1988 bats resembled those for 1973 bats. It is concluded that DDT played a major role in this severe population decline. These results can be applied by management personnel in evaluating the present and future status of this population regarding persisting organochlorine insecticides as well as other agricultural chemicals now in use. The case of the Carlsbad colony is discussed relative to the general issue of other bat population declines.
In Ovo Exposure to Polychlorinated Biphenyls: Reproductive Effects on Second-Generation American Kestrels by K. J. Fernie; J. E. Smits; G. R. Bortolotti; D. M. Bird (pp. 544-550).
The reproductive success of wild birds has been affected by exposure to multiple contaminants. Reproduction of captive American kestrels (Falco sparverius) was suppressed when adult birds were exposed to dietary polychlorinated biphenyls (PCBs). In this study, the reproductive effects of in ovo exposure to PCBs is explored, along with determining effects on reproduction in second-generation birds indirectly exposed to PCBs. Reproductive changes in this subsequent generation are examined separately in male and female birds. Captive American kestrels (F. sparverius) were hatched from clutches with eggs containing environmentally relevant levels of total PCBs (34.0 μg/g whole egg WW versus 0 μg/g controls); parent birds had been fed PCB-spiked (Aroclor 1248:1254:1260) food (7 mg/kg BW day−1) for 100 days until their eggs hatched. In 1999, the second-generation PCB birds were paired with unexposed kestrels having reproductive experience. In ovo PCB exposure suppressed egg laying completely in 25% of PCB females and resulted in delays in clutch initiation and smaller clutch sizes for PCB male and female pairs. There was no evidence in this study of in ovo PCB treatment effects on fertility or hatching success. The decline in reproductive success was also reflected in the reduced fledging success and higher incidence of complete brood mortality of PCB nestlings. Differences between in ovo–exposed PCB males and females but not between controls were evident in reproductive success. In ovo PCB exposure appears to have had greater effects on female kestrels until clutch completion, with a greater time lag between pairing and egg laying, reduced numbers of pairs laying eggs, and smaller clutches being laid. In ovo PCB exposure has greater effects later in the breeding season on male kestrels, which had poorer hatching and fledging success relative to the PCB females. Possible behavioral and physiological mechanisms involved in these reproductive changes are discussed.
Comparison of Heavy Metal Concentrations in Tissues of Red Foxes from Adjacent Urban, Suburban, and Rural Areas by R. Dip; C. Stieger; P. Deplazes; D. Hegglin; U. Müller; O. Dafflon; H. Koch; H. Naegeli (pp. 551-556).
The red fox (Vulpes vulpes) is a representative of the canid family with wide distribution in the Northern Hemisphere and Australia. The increasing utilization of urbanized habitats by red foxes prompted us to test whether this species may be used to monitor the presence of anthropogenic pollutants in cities or suburbs. For that purpose, we compared the concentrations of heavy metals (Cd, Pb, Cu, Zn) in foxes from urban, suburban, and rural areas within the municipality of Zürich (Switzerland). The kidney and liver of suburban and rural foxes contained the highest Cd concentrations, whereas urban foxes contained the highest Pb levels. In the kidney of suburban foxes, Cd concentrations increased from a median value of 0.73 mg/kg in juvenile animals to 1.82 mg/kg in adults. Similarly, the liver of suburban foxes contained increasing Cd levels from a median of 0.21 mg/kg in juvenile animals to 0.94 mg/kg in adults. An age-dependent storage of Cd was also found in foxes from the rural surroundings, but no such accumulation occurred in urban foxes from the city center, where even adult animals contained very low Cd levels. Conversely, foxes from the urban center were characterized by elevated Pb concentrations during the first 2 years of life, but this transient Pb accumulation was absent in suburban or rural animals. The liver of juvenile foxes contained a median Pb concentration of 0.99 mg/kg in the city compared to only 0.47 and 0.37 mg/kg in the suburban and rural area, respectively. Thus, we found that animals from separate environmental compartments contain different patterns of tissue residues, implying that red foxes may serve as a bioindicator species to detect certain toxic hazards in urbanized habitats.
Organochlorine Pesticides in Water, Sediment, Crops, and Human Fluids in a Farming Community in Ghana by W. J. Ntow (pp. 557-563).
A total of 208 samples of water, sediment, tomato crops, blood, and mothers' breast milk were collected from the environs of Akumadan, a prominent vegetable-farming community in Ghana. The samples were analyzed for organochlorine (OC) pesticide residues. Lindane and endosulfan were found in water and sediment, while other OC pesticide residues, such as hexachlorobenzene (HCB), p,p′-DDE, and heptachlor epoxide, were additionally found in sediment. Heptachlor epoxide was the only OC residue detected in appreciable quantity in crops. Significantly higher HCB and p,p′-DDE residues were found in blood and milk samples. The mean values of HCB and p,p′-DDE in blood were 30 μg/kg and 380 μg/kg, respectively. The mean values of HCB and p,p′-DDE in milk were 40 μg/kg fat (1.75 μg/kg whole milk) and 490 μg/kg fat (17.15 μg/kg whole milk), respectively. The presence of OC pesticide residues in breast milk requires further monitoring and epidemiological studies to clarify possible detrimental health effects in breast-fed infants.
Polybrominated Diphenyl Ethers in Swedish Human Liver and Adipose Tissue by D. Meironyté Guvenius; Å. Bergman; K. Norén (pp. 564-570).
Paired samples of human liver and adipose tissue were analyzed for polybrominated diphenyl ethers (PBDEs) containing 3–6 bromine atoms. The samples were obtained at autopsy from one woman and four men at the age of 47 and 66–83 years, respectively. PBDEs were found in all samples. The sum of nine PBDE congeners ranged 5–18 ng/g lipids and 4–8 ng/g lipids in liver and adipose tissue, respectively. In three paired samples the concentrations were similar in liver and adipose tissue, while in two of the pairs the concentrations were higher in liver than in adipose tissue. The PBDE congeners 2,2′,4,4′-tetraBDE (BDE-47), 2,2′,4,4′,5-pentaBDE (BDE-99), and 2,2′,4,4′,5,5′-hexaBDE (BDE-153) occurred at highest levels and constituted together 87–96% and 84–94% of the total sum of PBDEs in liver and adipose tissue, respectively. The levels of PBDEs were compared to those of polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), 1,1-bis(4-chlorophenyl)-2,2-dichloroethene (p,p′-DDE), and hexachlorobenzene (HCB).
Continuous Surveillance of Organochlorine Compounds in Human Breast Milk from 1972 to 1998 in Osaka, Japan by Y. Konishi; K. Kuwabara; S. Hori (pp. 571-578).
The presence of chlorinated organic compounds in breast milk of lactating women living in Osaka Prefecture, Japan, has been followed since 1972. Following the highest concentration found at the start of the measurements, contamination by polychlorinated biphenyls (PCBs) and organochlorine pesticides, such as β-HCH and DDT declined to about 3–13% of the peak levels by the mid-1970s and continued to decrease to low-level equilibrium states. This decline varies greatly with the chemical compound. In comparison with 1970s, when the contamination of breast milk was highest, the β-HCH level fell to about 3%, DDT to about 7%, and PCBs to about 13%, representative of different half-lives in the environment and the particular persistence of PCB. In the case of chlordane, a termite insecticide, more than 10 years have passed since its use was prohibited in Japan, but it continues to be found in human breast milk, although at a low level.
Urinary Bromide Levels Probably Dependent to Intake of Foods Such As Sea Algae by Z.-W. Zhang; T. Kawai; A. Takeuchi; Y. Miyama; K. Sakamoto; T. Watanabe; N. Matsuda-Inoguchi; S. Shimbo; K. Higashikawa; M. Ikeda (pp. 579-584).
The purpose of the present study is to examine if the bromide (Br) level in urine (Br-U) varies substantially among adult general populations of either sex or of different dietary habits. For this purpose, morning spot urine samples (about 50 per group) were collected from six groups of people, i.e., one group each of men and women in a city in Japan (thus two groups in Japan) and one group each of women in two urban and two rural areas in central and northeast China (four groups in China). The samples were analyzed for Br by ECD-gas chromatography after derivatization to methyl bromide. Br-U essentially followed a normal distribution. Whereas there was only a marginal difference in Br-U between men (7.7 ± 2.5 mg/L as an arithmetic mean and arithmetic standard deviation) and women (8.1 ± 2.9 mg/L) in Japan, and no difference between the urban (2.3 ± 0.8 mg/L) and rural women (2.6 ± 1.1 mg/L) in China, the difference between Japanese (8.1 ± 2.9 mg/L) and Chinese women (2.3 ± 0.8 mg/L for two cities and 2.6 ± 1.1 mg/L for two villages) was substantial. A literature survey suggested variation in dietary habits, especially that in sea algae intake, is a possible factor affecting the observed difference in Br-U between the two ethnic groups. Contribution of Br in cereals after fumigation with, e.g., methyl bromide, was also thought to be possible. The implication of difference in background Br-U levels is discussed in relation to biological monitoring of exposure to Br-containing industrial chemicals, such as 1- and 2-bromopropane.