Urinary excretion of inorganic arsenic and its metabolites after repeated ingestion of sodium metaarsenite by volunteers

Summary Arsenic (125, 250, 500 or 1000 g as NaAsO₂) was administered orally once a day for five consecutive days to 4 volunteers who refrained from eating marine organisms during the experiment. Urine was collected during 24-h periods starting one day before the first administration and up to 14 days later. The following determinations were performed: total arsenic, inorganic arsenic (As;), monomethyl arsenic (MMA) and dimethylarsinic (DMA) acids. In each case, the sum of As;, MMA and DMA approximated very closely the urinary concentration of total arsenic determined after mineralisation of the urine sample. It was concluded that these arsenicals are the only metabolic forms of arsenic following absorption of inorganic arsenic. Since a steady state in the urinary excretion of arsenic is reached within 5 days, our results demonstrated that at equilibrium, the total amount of arsenic excreted in urine per day amounts to 60% of the ingested dose. Speciation of the arsenic metabolites in urine indicated that the arsenic methylation capacity of the human body was not yet saturated, even with an oral daily dose of 1000 g As for 5 days. However, when the administration of arsenic was stopped, the biological half life of arsenic in urine increased slightly with the dose (from 39 h at 125 g to 59 h at 1000 g). Determination of inorganic arsenic, MMA and DMA in urine appears to be the method of choice for the biological monitoring of workers exposed to inorganic arsenic since these measurements are not influenced by the presence of organoarsenicals from marine origin. From the linear relationship found in this study between arsenic administered and that excreted in urine, it was estimated that a time-weighted average exposure of 50 g As/m³ would lead to an average urinary excretion of 220 g As (sum of As_i, MMA and DMA) per gram creatinine.     

Toxicity of the herbicides 2,4-D,DEF, propanil and trifluralin to the Dungeness crab,Cancer magister

Lethal and sublethal responses to the herbicides 2,4-D, DEF®, propanil, and trifluralin of various life history stages of the Dungeness crab,Cancer magister, were examined to estimate maximum acceptable toxicant concentrations (MATC) of each compound for this species. Zoeae were found, in long term tests, to be the most sensitive stage. Based on the experiments with this stage, MATCs were concluded to be >0.95, <6.9g for DEF, 26, <220g/L for trifluralin, 80, < 1,700g/L for propanil, and < 1,000g/L for the free acid form of 2,4-D.Technical Paper No. 4819, Oregon Agricultural Experiment Station     

Monitoring lead pollution near a storage battery recycling plant in Taiwan, Republic of China

This study presents the distribution of blood lead levels and lead in various environmental samples (water, sediments, soils, and air) near the Shing-Yie storage battery recycling plant in Taiwan before (July 1990 to June 1991) and after (July 1992 to June 1993) amelioration. Before amelioration, the average blood lead levels in the neighborhood of the plant were in the range of 10.55±5.7 to 12.28±7.9 g/dl. After amelioration, relatively lower average concentrations of blood lead (range 8.35±3.0 to 9.13±2.5 g/dl) were generally found; however, these averages were still higher than that (7.79±3.5 g/dl) from other lead-unpolluted areas of Taiwan. An exceedingly high geometric mean (GM) lead concentration (128 g/L) was found in the downstream river water of the Tawulum River passing by the plant. The concentrations of lead (GM=372 and 418 g/g) in the downstream river sediments were higher than those (GM=123 and 158 g/g) in the upstream river sediments before and after amelioration, respectively. Furthermore, lead species in river sediments were analyzed by a sequential leaching technique. The sum of phases I, II, and III accounted for 83.7% of total lead at station R₂ (nearest to the plant). Maximum lead concentration (GM=2402 g/g) in dust at the soil surface from station S₁ (nearest to the plant) was much higher than those from the other stations by about 18 times before amelioration. However, the maximum value dropped to 1,155 g/g after amelioration. On the whole, the geometric mean concentration of lead in dust at the soil surface nearest to the plant was >1,000 g/g and decreased to <100 g/g in the 15–30 cm depth soil about 2 km away from the plant. Before amelioration, the geometric mean lead concentration of 4.57 g/m³ (range 0.102–37.6 g/m³) in the air near the plant was higher than that at the background locations, the geometric mean value of which was 0.08 g/m³.     

Nitrous oxide in blood and urine of operating theatre personnel and the general population

Nitrous oxide (N₂O) was assayed in 676 urine samples and 101 blood samples provided after exposure by operating theatre personnel from nine hospitals. The blood and urine assays were repeated in 25 subjects 18 h after the end of exposure. For 80 subjects, environmental N₂O was also measured during intraoperative exposure. Mean urinary N₂O in the 676 subjects at the end of exposure was 40 g/l (range 1–3805 g/l); in 10 of the 676 subjects, urinary N₂O was in the range 279–3805 g/l (mean 1202 /l). The 98^th percentile was 120 g/l. Mean blood N₂O at the end of exposure, measured in 101 subjects, was 21 g/l (median 16 g/l, range 1–75 g/l). Blood and urine N₂O (1.5 g/l and 4.9 g/l, respectively) in 25 subjects, 18 h after exposure, was significantly higher than in occupationally non-exposed subjects (blood 0.91 g/l, urine 1 g/l). Environmental exposure was significantly related to blood and urinary N₂O (r = 0.59 andr = 0.64, respectively). Blood and urinary N₂O were significantly related to each other (r = 0.71), and were equivalent to about 25% of the environmental exposure level. The mean urinary N₂O of 1202 g/l in 10/676 subjects was not related to environmental exposure in the operating theatre. The highest urinary N₂O levels measured in these 10/676 subjects could be explained by an asymptomatic urinary infection.     

Acute and chronic toxicities of arsenic(III) to fathead minnows,flagfish, daphnids,and an amphipod

Acute and chronic toxicities of arsenic (III) (As) to four species of freshwater organisms were determined. All tests were flow-through exposures except the daphnid (Daphnia magna) tests which were static concentration renewal exposures. Acute exposures of fathead minnows (Pimephales promelas), flagfish (Jordanella floridae), and an amphipod (Gammarus pseudolimnaeus) to As resulted in 96-hr LC₅₀ or EC₅₀ estimates of 14,100, 14,400, and 874 g/L, respectively. Daphnids were exposed to As with and without food resulting in 96-hr EC₅₀ estimates of 4,340 and 1,500 g/L, respectively. Chronic exposures of 28 to 31 days duration were made for fathead minnows, flagfish, and daphnids. The chronic limit ranges (highest tested exposure concentration having no adverse effect and the lowest tested exposure concentration having an adverse effect) based upon the most sensitive measured parameters of body length and wet weight were 2,130 to 4,300 g/L for fathead minnows and 2,130 to 4,120 g/L for flagfish. Daphnids had chronic limits of 633 to 1,320 g/L based upon survival and the measured parameters of reproduction and body length. Calculation of an acute test/chronic test ratio for fathead minnows, flagfish, and daphnids (fed and unfed) resulted in a range of values from 1.64 to 4.80.     

Occupational chronic exposure to metals

Summary External and internal chromate exposure of 103 stainless steel welders who were using manual metal arc welding (MMA), metal inert gas welding (MIG) and both methods, were measured by ambient and biological monitoring. At the working places the maximum chromium trioxide concentrations were 80 g/m³. The median values were 4 g/m³ (MMA) and 10 g/m³ (MIG). The median chromium concentrations in erythrocytes, plasma and urine of all welders were < 0.60, 9.00 and 32.50 g/l. For biological monitoring purposes, chromium levels in erythrocytes and simultaneously in plasma seem to be suitable parameters. According to our results, chromium levels in plasma and urine in the order of 10 and 40 g/l seem to correspond to an external exposure of 100 g chromium trioxide per cubic metre, the technical guiding concentration (TRK-value). Chromium concentrations in erythrocytes greater than 0.60 g/l indicate an external chromate exposure greater than the TRK-value.     

Effects of mercury,selenium, and organochlorine contaminants on reproduction of Forster's terns and black skimmers nesting in a contaminated Texas Bay

Mean mercury (0.40 g/g), and geometric mean DDE (1.6 g/g) and polychlorinated biphenyl (PCB) (2.3 g/g) concentrations in Forster's tern (Sterna forsteri) eggs from Lavaca Bay were higher than those in tern eggs from a reference area in San Antonio Bay, but residues were not correlated with hatching success. Nest success was similar between bays. Selenium levels in Lavaca Bay tern eggs (0.71 g/g) were also comparable to those in eggs from the reference area (0.68 g/g).Clutch size (3.1 to 3.4) of Lavaca Bay black skimmers (Rynchops niger) was no different than that (3.4) at a reference colony near Laguna Vista. Nest success was similar among three Lavaca Bay colonies, but success was lower at one Lavaca Bay colony (40%) than at Laguna Vista (65%). Mean mercury (0.46 g/g) and selenium (0.75 g/g) concentrations in skimmer eggs from Lavaca Bay were higher than those (0.19, 0.33 g/g) from Laguna Vista; however, concentrations of neither contaminant were related to hatching success. DDE concentrations in Lavaca Bay skimmer eggs (3.4 g/g) were similar to those from Laguna Vista (3.2 g/g) and DDE was negatively correlated with hatching success. PCBs were higher in eggs from Lavaca Bay (1.3 g/g) than Laguna Vista (0.8 g/g). Organochlorine and metal contaminants in most eggs were below embryotoxic levels. Eggshell thinning in Forster's terns (7%) and black skimmers (5%) was below that associated with lowered reproduction.DDE and PCBs were detected in 9 Caspian tern (S. caspia) eggs; maximum concentrations were 4.7 and 5.4 g/g. Caspian tern and least tern (S. albifrons) eggs contained low (0.9 g/g) concentrations of mercury and selenium.     

Hexahydrophthalic acid in urine as an index of exposure to hexahydrophthalic anhydride

Summary Post-shift and next-morning urine was sampled from workers exposed to hexahydrophtalic anhydride (HHPA), an epoxy hardener, sensitising at low exposure levels. Exposure levels of HHPA in air gas chromatography, GC) in the range of 30–270 g/m³ corresponded to urinary concentrations of 0.9–2.8 mol hexahydrophthalic acid (HHP acid; GC-mass spectrometry)/mmol creatinine. In the morning samples the concentrations were <0.04-0.3 mol HHP acid/mmol creatinine. In unexposed controls, the level was <0.1 mol/mmol creatinine. A correlation was found between the time-weighted levels of HHPA in air and HHP acid in the post-shift urine (r _s = 0.93; P < 0.023), indicating that the determination of HHP acid in urine is suitable for biologic monitoring of HHPA exposure.     

Mercury and methylmercury in population risk groups on the Atlantic coast of Southern Spain

The presence of methylmercury and total mercury in the hair of high risk groups residing in the highly industralized South Atlantic coastal area of Spain were studied. In fishermen, total mercury and methylmercury content showed slight non-statistically significant differences among groups from two different coastal areas (geometric means: 10.41 and 8.36 g/g for total mercury; 8.28 and 6.72 g/g methylmercury). Mercury content in both groups differed significantly from controls (geometric mean 2.5 g/g total mercury, 4.50 g/g for methylmercury; p<0.05). In pregnant women, statistically significant differences were found in the three groups (two coastal areas and controls). Geometric means were 2.40, 5.94, and 0.94 g/g for total mercury and 1.93, 4.78, and 0.82 g/g for methylmercury. Results were compared with those obtained in other European countries in the Mediterranean area. Simultaneously, the same compounds were analyzed in fish and molluscs from those most consumed by people in the above-mentioned groups. The following results were obtained: sword fish, 1.57±1.27 g/g and 1.20±0.94 g/g for total mercury and methylmercury respectively; Scrobicularia plana, 0.07±0.052 and 0.053±0.039 g/g; Tapes decussatus, 0.046±0.20 and 0.039±0.018 g/g.     

Seasonal variation of trace metal concentrations in the digestive gland of the Mediterranean mussel Mytilus galloprovincialis: Comparison between a polluted and a non-polluted site

Seasonal changes in metal (Cu, Fe, Mn, Pb, and Zn) concentrations were observed in the digestive gland of the Mediterranean mussel, Mytilus galloprovincialis, from both a polluted and a non-polluted population. Digestive gland of mussels from the polluted site showed metal concentrations appreciably higher than in non-polluted organisms, especially for Pb (up to 160 g/g d.w.), Mn (up to 300 g/g d.w.), and Fe (up to 8,500 g/g d.w.), whereas the two populations showed maximum mean values, respectively, of 34 and 20 g/g d.w. for Cu and 170 and 120 g/g d.w. for Zn.Over 1 year (1991), differences between maximum and minimum values were moderate only in the unpolluted organisms. During gametogenesis, while the metal concentrations (expressed as g/g dry weight) decreased in the digestive gland, the tissue burden (as g) in that organ remained nearly constant or increased slightly.The apparent decrease in metal concentrations was probably due to the penetration of gonadic tissues into the digestive gland during gametogenesis, which biologically diluted metal concentrations in mussels from both the polluted and unpolluted populations. The effect of mussel size on trace metal concentrations in the digestive gland was demonstrated during different stages of the reproductive cycle. Higher concentrations were found in smaller organisms; however, during the spawning period, due to the fact that this is not a synchronous process within a population, the organisms exhibit a high variability in digestive gland weight which can mask this relationship when digestive gland weight is used as a size-index and as a parameter of the trace metal digestive gland burden.     

Sublethal Effects of Trace Metals (Cd,Cr, Cu,Hg) on Embryogenesis and Larval Settlement of the Ascidian <Emphasis Type="Italic">Ciona intestinalis</Emphasis>

Toxicity of Cadmium (Cd), Chromium (Cr), Copper (Cu), and Mercury (Hg) on the early developmental stages of Ciona intestinalis was investigated. Developmental defects of larvae after exposure of gametes throughout their development to the larval stage were assessed. Gamete exposure to increasing metal concentrations resulted in a significant decrease of the percentage of normally hatched larvae, showing median effective concentrations (EC₅₀) of 721 g/L (6.42 M) for Cd, 12772 g/L (226 M) for Cr, 36.6 g/L (0.576 M) for Cu, and 44.7 g/L (0.223 M) for Hg. Larval attachment was significantly affected when gametes were exposed to the metals throughout development. The EC₅₀ reducing larval attachment by 50% were 752 g/L (6.7 M) for Cd, 15026 g/L (289 M) for Cr, 67.8 g/L (1.607 M) for Cu, and 78.1 g/L (0.389 M) for Hg. Therefore, on a molar basis Hg is three times more toxic than Cu, 20–30 times more than Cd, and 700–1000 times more toxic than Cr, for both responses.     

Biological monitoring of occupational exposure to toluene diisocyanate

Summary The study validated the use of urinary toluene diamine (TDA) in postshift samples as an indicator of preceding 8-h exposure to toluene diisocyanate (TDI). Nine workers exposed in TDI-based polyurethane foam production were studied. Their exposure levels varied in 8-h time-averaged samples from 9.5 to 94 g/m³. The urinary TDA concentrations varied from 6.5 to 31.7g/g creatinine and they were linearly related to the atmospheric TDI levels. Approximately 20% of TDI is metabolized to diamines but their specificity is remarkable to the extent that by analysis for the 2,4- and 2,6-diamino isomers an idea of the percutaneous absorption may be had.     

Development of the surf clam (Spisula solidissima) following exposure of gametes,embryos, and larvae to silver

The gametes, embryos, and early larvae of the surf clamSpisula solidissima were exposed to silver at concentrations up to 65 g/L. All experiments were conducted at 20°C and 30 S, and lasted up to 48 hr after fertilization. Forty-five minute exposures of eggs to 16 g/L or more silver just prior to fertilization in non-silver seawater lead to production of abnormal larvae. Simultaneous exposures of eggs and sperm to silver concentrations up to 21 g/L for 45 min did not prevent fertilization but did produce abnormal larvae at silver concentrations greater than 6 g/L. Postfertilization treatments of zygotes, embryos, and larvae lead to fewer abnormalities than prefertilization or fertilization treatments of comparable exposure length and concentration. The greatest numbers of abnormalities and mortalities were observed in continuous exposures, from gametes through fertilization to 48 hr postfertilization. Variability in % normal development was greater in high than in low silver concentrations.     

Comparative toxicity of arsenic compounds and their accumulation in invertebrates and fish

The toxicity of arsenic III, arsenic V, sodium dimethyl arsenate, and disodium methyl arsenate to stoneflies, snails, amphipods, and trout, and the bioaccumulation of these compounds were studied during a 28-day flow-through test.Daphnia magna were exposed for 21 days in static tests to determine life-cycle effects. All animals were exposed to concentrations of approximately 100 and 1000g/L (as arsenic) of each of the compounds. Arsenic III, the most toxic compound, caused a significant reduction in the survival of amphipods at 1000g As/L after seven days. None of the compounds significantly affected the survival of other test species after 28 days or reduced young production inDaphnia after 14 days of exposure. The concentration of accumulated arsenic in stoneflies, snails,and Daphnia was as much as 131, 99, and 219 times greater than the water concentration, whereas amphipods and rainbow trout contained arsenic residues similar to the controls. Residues in stoneflies, snails, andDaphnia exposed to 1000g As/L were higher than those in animals exposed to 100g As/L, but appeared to reach a steady state after 14 days. Total arsenic accumulation was greatest in organisms exposed to inorganic arsenic, particularly at 100g/L.     

Comparison of atomic absorption and fluorescence spectroscopic methods for the routine determination of urinary arsenic

Objective: Interpretation of urinary arsenic measurements is sometimes difficult because of the absorption of seafood that contains trimethylated arsenic forms (arsenobetaine and arsenocholine). The objective of this study was to develop a rapid and robust technique for the measurement of the sum of inorganic arsenic metabolites. Methods: Measurement of arsenic was performed in urine after hydride generation in acid medium. Using atomic fluorescence spectrometry (AFS) as the detection system, we developed a rapid (one determination in less than 2min) technique using 50 l urine without pre-treatment. Standardisation was done externally with a mixed standard solution containing inorganic trivalent arsenic (As_i^III), inorganic pentavalent arsenic (As_i^V), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) (15/15/12.5/57.5) Results: Samples distributed in the frame of an international comparison programme were used to assess accuracy of the AFS procedure, which gives a linear response up to 50 g/l and proves more precise [coefficient of variation (CV)< 4% at 5 g/l] and sensitive than the atomic absorption spectroscopy (AAS) technique using a quartz cell. An additional adaptation that allows the detection of non-directly reducible arsenic forms has also been validated for samples with high arsenic concentrations. Conclusions: The present study demonstrates the superiority of AFS over atomic absorption spectrometry (AAS) in arsenic determination and the interest of online mineralisation prior AFS detection for the determination of arsenic concentration in urine.     

Levels of polychlorinated biphenyls,DDE, and mirex in waterfowl collected in New York State, 1979–1980

Levels of polychlorobiphenyls (PCBs), DDE, and mirex were measured in the subcutaneous fat, breast muscle, liver, and brain of sixty-three waterfowl collected in New York State during 1979 and 1980. Mean PCB levels were 7.5 g/g in fat and 1.3 g/g in breast muscle on a wet weight basis. The FDA tolerance level is 3.0 g/g in fat on a wet weight basis. Mean DDE and mirex levels were 0.34 g/g and 0.10 g/g in fat and 0.16 g/g and 0.07 g/g in breast muscle on a wet weight basis, respectively. Comparisons and correlations were made of contaminant levels in the various tissues by different concentration bases, and PCB concentrations were compared to the Aroclor^® (PCB) type. Potential health hazards are discussed. Comparisons to earlier studies show declined levels. Mergansers are the most contaminated species.     

Comparative Embryonic and Larval Developmental Responses of Estuarine Shrimp (<Emphasis Type="Italic">Palaemonetes pugio</Emphasis>) to the Juvenile Hormone Agonist Fenoxycarb

Grass shrimp (Palaemonetes pugio) were reared separately through both embryonic and total larval development during exposure to fenoxycarb at measured concentrations of <2.2 to 888 g L^–1. A fenoxycarb concentration of 888 g L^–1 significantly (p < 0.05) inhibited embryonic development to larval hatching and extended the embryonic developmental period from 11.9 to 12.7 days. Exposure to fenoxycarb concentrations 502 g L^–1 had no significant (p > 0.05) effect on complete embryonic development. Significantly fewer shrimp successfully metamorphosed to postlarvae when exposed through complete larval development to fenoxycarb concentrations 4 g L^–1. Larval development of grass shrimp was therefore >2 orders of magnitude more sensitive to this juvenile hormone agonist than was embryonic development. Viability of larvae developing in fenoxycarb was concentration dependent. Development beyond third zoeal stage was significantly inhibited at fenoxycarb concentrations 190 g L^–1, whereas development beyond fourth zoeal stage was inhibited by a concentration of 45 g L^–1. Fenoxycarb exposure of developing larvae did not alter either the duration of total larval development or the total number of larval stages before metamorphosis. Rearing of fenoxycarb-exposed embryos through larval development without further exposure had no significant effect on number of larval stages, larval development rate, or metamorphic success of larvae. Similarities in the sensitivity of grass shrimp larvae and mosquito larvae to fenoxycarb suggests that the use of a bioassay protocol measuring the metamorphic success of crustacean larvae would be a valuable adjunct to the hazard assessment of newly developed pesticides that target endocrine control of metamorphosis in insects and possibly other endocrine-disrupting xenobiotics as well.     

Chronic toxicity of the bromoxynil formulation Buctril® to Daphnia magna exposed continuously and intermittently

Two chronic toxicity tests were conducted in which Daphnia magna were either continuously or intermittently exposed to bromoxynil octanoate (BO; as Buctril^®) for 28 d. In the intermittent exposure test, daphnids were exposed to daily pulses of BO with 24-h mean concentrations equal to those in the continuous exposure test, and the peak concentrations were three times the 24-h mean values. After 28 d of continuous exposure to BO, survival of daphnids was reduced at 80 g/L, whereas mean number of young per adult, intrinsic rate of natural increase, and mean weight of adults were all reduced at 40 g/L. Intermittent exposures to daily pulses of BO for 28 d caused reduced survival of daphnids at 24-h mean concentrations 40 g/L and reduced mean number of young per adult, intrinsic rate of natural increase, and mean weight of adults at 24-h mean concentrations 20 g/L. The estimated geometric mean-maximum acceptable toxicant concentrations of BO based on 24-h mean nominal values were 28 g/L for continuous exposures and 14 g/L for intermittent exposures. These results demonstrated that continuous-exposure studies may not be adequate in assessing herbicide toxicity to aquatic biota when concentrations fluctuate temporally.     

The effects of poly chlorinated biphenyls and methylmercury,singly and in combination on mink. II: Reproduction and kit development

Adult ranch-bred mink (Mustela vison) were fed diets containing either 0, 1.0 g/g polychlorinated biphenyls (PCB) (Aroclor^® 1254), 1.0 g/g methylmercury (MeHg), a combination of 1.0 g/g PCB plus 1.0 g/g MeHg, or 0.5 g/g PCB plus 0.5 g/g MeHg. Fertility of adult male mink, percentage of females whelped or number of kits born per female were not affected by the treatments. However, growth rate of kits nursed by mothers exposed to 1.0 g/g PCB was significantly reduced. There was a synergistic effect of PCB and MeHg which reduced kit survival in groups receiving both chemicals simultaneously. Kit survival to weaning in the control, 0.5 g/g PCB/MeHg, and 1.0 g/g PCB/MeHg groups was 72.0%, 62.7% and 35.8%, respectively. The results suggest that growth and survival of mink kits are adversely affected at dietary levels of PCB and MeHg currently present in some environments.     

Urinary 1-naphthol and 1-pyrenol as indicators of exposure to coal tar products

Chemical exposure of assemblers handling creosote-impregnated wood and of a single worker chiselling coal tar pitch layer was assessed by measuring airborne naphthalene and various polycyclic aromatic hydrocarbons (PAHs), and by measurement of urinary excretion of 1-naphthol and 1-pyrenol. The sum concentration of PAHs and of 4–6 aromatic ring-containing PAHs were high, 440 g/m³ and 290 g/m³, respectively, when chiselling. In the assembler's workplace, the PAH concentrations were about 1/50 of this value. Regarding airborne naphthalene concentrations the situation was reversed (assemblers, 1000 g/m³; chiseller, 160 g/m³). Correspondingly, the assemblers' urinary 1-napthol concentrations were 15–20 times higher than those of the chiseller. The urinary 1-pyrenol concentration of the chiseller was 2–4 times higher than among the assemblers. As the estimated pyrene inhalation doses among the assemblers could account for only about 2%–25% of the 24-h pyrenol excretion in urine, the skin was presumably the main route of uptake. For an assessment of the exposure to PAHs, air measurements, monitoring of metabolites in urine and preferably also data on the composition of the skin-contaminating product are needed.