Reproduction and growth of progeny of female mice mated after treatment with crufomate

Effects on reproduction and litter growth were studied for two successive reproductive periods (RP)--interval between caging females with males and whelping--in female mice treated dermally with crufomate at 100 or 50 mg/kg on days 35 and 21 before caging with untreated males. Each treatment with crufomate caused about 50% reversible inhibition of cholinesterase activity without inducing any signs of toxicity. The higher dose reduced the conception rate and the number of litters and young born and weaned during the two RPs. It also reduced the lactation index, weaning weight of males and females, and mature weight of males in the first litter. The lower dose prolonged the gestation period and reduced the lactation index and the number of litters and young weaned in the first RP and conception rate and number of litters and young born and weaned in the second RP. The lower dose reduced the weaning and mature weights of the first litter and mature weight of males in the second litter. The higher dose reduced the body weight and the lower dose increased the adrenal weight of the treated females.     

Sensitivity analysis of a parameterization of the stomatal component of the DO3SE model for Quercus ilex to estimate ozone fluxes

A sensitivity analysis of a proposed parameterization of the stomatal conductance (g(s)) module of the European ozone deposition model (DO(3)SE) for Quercus ilex was performed. The performance of the model was tested against measured g(s) in the field at three sites in Spain. The best fit of the model was found for those sites, or during those periods, facing no or mild stress conditions, but a worse performance was found under severe drought or temperature stress, mostly occurring at continental sites. The best performance was obtained when both f(phen) and f(SWP) were included. A local parameterization accounting for the lower temperatures recorded in winter and the higher water shortage at the continental sites resulted in a better performance of the model. The overall results indicate that two different parameterizations of the model are needed, one for marine-influenced sites and another one for continental sites.     

Comparison of particle light scattering and fine particulate matter mass in central California

Particle light scattering (Bsp) from nephelometers and fine particulate matter (PM2.5) mass determined by filter samplers are compared for summer and winter at 35 locations in and around California's San Joaquin Valley from December 2, 1999 to February 3, 2001. The relationship is described using particle mass scattering efficiency (sigmasp) derived from linear regression of Bsp on PM2.5 that can be applied to estimated PM2.5 from nephelometer data within the 24-hr filter sampling periods and between the every-6th-day sampling frequency. An average of sigmaSp = 4.9 m2/g was found for all of the sites and seasons; however, sigmasp averaged by site type and season provided better PM2.5 estimates. On average, the sigmasp was lower in summer than winter, consistent with lower relative humidities, lower fractions of hygroscopic ammonium nitrate, and higher contributions from fugitive dust. Winter average sigmasp were similar at non-source-dominated sites, ranging from 4.8 m2/g to 5.9 m2/g. The sigmasp was 2.3 m2/g at the roadside, 3.7 m2/g at a dairy farm, and 4.1 m2/g in the Kern County oilfields. Comparison of Bsp from nephelometers with and without a PM2.5 inlet at the Fresno Supersite showed that coarse particles contributed minor amounts to light scattering. This was confirmed by poorer correlations between Bsp and coarse particulate matter measured during a fall sampling period.     

Using experimental and forest soils to investigate the uptake of polycyclic aromatic hydrocarbons (PAHs) along an urban-rural gradient

Spatial and temporal variation in the atmospheric deposition of PAHs to soil was examined by deploying experimental soils for approximately 165 days and conducting a survey of forest soils at several sites along an urban-rural transect extending from downtown Toronto to approximately 80 km north of the city. PAH concentrations decreased with distance from the urban centre-by a factor of 2 and 60 for the experimental and forest soils respectively. The large gradient for the forest soils is generally consistent with air concentrations of PAHs measured using high volume and passive air samplers. The smaller gradient for the experimental soils was due to kinetic limitations of PAH accumulation and the relatively short deployment period of approximately 165 days. Mean effective deposition velocities (gas+particle) for the full range of PAHs for the experimental soils at the urban, suburban, and the rural sites were 2, 31 and 26 cm s(-1), respectively. These were incorporated into a dynamic model that was used to assess the long-term uptake of PAHs in forest soils. Model results indicate that lower molecular weight PAHs may achieve equilibrium and become involved in soil-air exchange whereas higher molecular weight PAHs are accumulated for much longer time periods.     

Growth and nutrition of Quercus rubra L. seedlings and mature trees after three seasons of ozone exposure

Seedling growth and nutritional status have been shown to be sensitive to ozone, but the influence of multi-season ozone exposure on mature tree growth and nutrition has not been examined. To determine if seedlings and mature trees were similarly affected by ozone exposure, growth and nutrient concentrations in northern red oak (Quercus rubra L.) 4-year-old seedlings and 32-year-old mature trees were examined after treatment with subambient, ambient and twice ambient concentrations of ozone for three growing seasons. SUM00 values summed over the three growing seasons were 147, 255 and 507 ppm-h, respectively, for the subambient, ambient and twice ambient exposures. For mature trees, no influence of ozone treatment on lower stem diameter growth, stem growth within the mid-canopy and foliar biomass was observed. Seedling height was increased by ozone, but biomass and diameter were unaffected. A reduction in the specific leaf weight of leaves in response to ozone coincident with the loss of recurrent flushing was observed in seedlings. Ozone exposure reduced foliar nitrogen concentrations and increased woody tissue nutrient concentrations in seedlings and mature trees at the end of the third growing season. These results suggest an influence of ozone on retranslocation processes in seedlings and mature trees.     

Morphological, biochemical, and histopathological indices and contaminant burdens of cotton rats (Sigmodon hispidus) at three hazardous waste sites near Houston, Texas, USA

Male cotton rats (Sigmodon hispidus) were studied at three industrial waste sites near Houston, Texas, to determine whether various morphological, biochemical, and histopathological indices provided evidence of contaminant exposure and toxic insult. Only modest changes were detected in cotton rats residing at waste sites compared with reference sites. No single parameter was consistently altered, except hepatic cytochrome P-450 concentration which was lower ( [Formula: see text] ) at two waste sites, and tended to be lower ( [Formula: see text] ) at a third waste site. Elevated petroleum hydrocarbon concentrations were detected in rats at one waste site, but contaminant burdens of rats from the other sites were unremarkable. Unlike rats captured in summer, those trapped in winter exhibited hepatocellular hypertrophy and up to a 65% increase in liver: body weight ratio, cytochrome P-450 concentration, and activities of aniline hydroxylase, aryl hydrocarbon hydroxylase, and glutathione S-transferase. Although genotoxicity has been previously documented in cotton rats residing at two of the waste sites, biomarkers in the present study provided little evidence of exposure and damage.     

Concentrations of heavy metals in Sotalia fluviatilis (Cetacea: Delphinidae) off the coast of Ceará, northeast Brazil

Lead (Pb), cadmium (Cd) and mercury (Hg) concentrations on liver and kidney of Sotalia fluviatilis (Cetacea: Delphinidae) stranded in the coast of Ceará, Brazil, were studied from 1996 to 1999. Pb levels were usually lower than the detection limit (0.1 microg/g). Concentrations of Cd were significantly higher in kidney than liver, averaging 0.8 microg/g. Mercury accumulation took place mainly in liver with an average concentration of 4.6 microg/g. Both metals were significantly higher in larger mature individuals, but differences between sexes were not significant. The detection of Cd, Hg and Pb in tissue samples of S. fluviatilis off the coast of Ceará indicated that heavy metals are locally available in the water, and bioaccumulation may be occurring through the food web. Contamination levels were not considered critical, but could be related to Ceará's growing industrial development. The associated risks of pollution outfalls may pose a threat to marine organisms in a near future, especially for top predators such as S. fluviatilis.     

Chlorinated pesticides and PCBs in sediments and molluscs from freshwater canals in the Hanoi region

The concentrations of organochlorine pesticides and PCBs were determined in surface sediments and freshwater molluscs (Angulyagra sp.) from water canals in the region of Hanoi city. Results obtained show that the concentration of sigma DDT compounds in sediments range from 7 to 80 ng/g (dry weight) and from 6 to 864 ng/g (dry weight) in the soft tissues of molluscs. The concentrations of sigma DDTs were higher in populated sites and much lower in rural sites, indicating that the DDT has been used for mosquito control and not as a crop protection chemical. Hexachlocyclohexanes (HCHs) have also been widely used in the region but the current environmental concentrations are much lower than those of DDT's, which is due to the less persistence of those compounds. Polychlorinated biphenyls (PCBs) were measured, for example as aroclor 1254, in concentrations up to 40 ng/g (dry weight) and up to 76 ng/g (dry weight) in sediments and molluscs, respectively. Molluscs from water canals are a very popular food in the region. Taking into consideration the high DDT levels measured in these molluscs their consumption is worrisome and may expose the population to high levels of endocrine disrupting substances. Current PCB levels in sediments are lower than usually measured in industrialized countries. Therefore, PCB concentrations in aquatic molluscs are still also relatively low. These snails do not have enzyme ability to metabolize most of the CB congeners and, thus, are passive accumulators and a significant transfer pathway of CBs to consumers. Therefore, measures to phase out the use of these persistent and bioaccumulable chemicals should be adopted in order to prevent further environmental contamination.     

Bioaccumulation studies of organochlorinated pesticides in tissues of Cyprinus carpio

Freshwater fish Cyprinus carpio was selected for the study of bioaccumulation of organochlorinated pesticides in tissues like gills, muscle, intestine, kidney, and liver in a continuous fed system. The pesticides used were Aldrin, Dieldrin, BHC, and DDT. The bioaccumulation of Dieldrin was maximum of 85.0 microg g(-1) wet weight in liver tissue while minimum of 7.30 microg g(-1) wet weight for DDT at 30 days exposure time. Bioconcentration factor (BCF) has followed the same trend in liver tissue for Dieldrin and DDT. The rate of bioaccumulation was found to be maximum of 4.3879 microg g(-1) wet weight in liver tissue and minimum of 0.0021 microg g(-1) wet weight in gill tissue for 30 days exposure. As evidenced by the increasing values of BCF, pesticide uptake also showed increased trend with the increase in exposure time. A high correlation coefficient ranging between 0.7247 and 0.9616 between the pesticide concentration and exposure time was observed. Based on actual BCF values, log Kow were calculated and the values are well within the reported values of 6.5 indicating efficient relationship between BCF and log Kow because beyond the 6.5 the bioconcentration levels off.     

Manganese concentrations in maternal–infant blood and birth weight

Manganese (Mn) is an essential mineral nutrient in mammals. The physiological role of Mn in animal models is well documented, but little is known about the adverse effects of Mn deficiency or overexposure in humans, including pregnancy outcomes such as birth weight. We examined the relationship of the maternal and cord blood Mn levels with birth weight in a cohort of 172 mother–infant pairs born in Shanghai, China. Non-linear spline and quadratic regression models were used to test the hypothesis of an inverted U-shaped association between the Mn levels and birth weight. The median (range) levels of Mn in the maternal and cord blood were 5.38 (2.34–30.37) μg/dL and 7.66 (2.57–34.23) μg/dL, respectively. An inverted U-shaped relationship was observed between maternal Mn and birth weight after adjusting for potential confounders. The birth weight increased with Mn levels up to 4.18 μg/dL, and a slight reduction in weight was observed at higher levels. The cord blood Mn levels were not found to be associated with birth weight. Both lower and higher Mn exposures are associated with lower birth weight, which may influence important developmental parameters; the association of higher Mn levels with lower weight was weak and imprecise.     

Increasing concentrations of nitrogen dioxide pollution in rural Wales

Monitoring of nitrogen dioxide pollution was carried out in rural environments throughout Wales during a 1-year survey to quantify any changes in background concentrations and distribution of the pollutant since an earlier survey in 1986. There were 23 sites in the present survey of which 16 had been monitored during the 1986 survey. The remaining 7 sites were based on moorland in mid-Wales within map squares for which critical loads for soil acidification are expected to be exceeded by the year 2005. All sites were chosen so as to be remote from major local sources of NO(2) and the values obtained were deemed to be minimum concentrations for the different regions. Measurements were made using diffusion tubes which aimed to provide mean concentrations of NO(2) for 2-week exposure periods. Concentrations of NO(2) were found to be higher in the winter months for most sites and this is probably related to a greater use of fossil fuels for heating buildings at this time of year. The exception was the high concentrations of NO(2) in May and June for several sites in North Wales, and in July and August for a site on Mount Snowdon. These high summer concentrations in North Wales are thought to be related to increased traffic associated with tourism. It is apparent that there has been a substantial increase in rural concentrations of NO(2) throughout Wales since the earlier survey of 1986. As an average of all 16 sites used in both surveys, there was a 53% increase in the annual mean concentration of NO(2). Also, it is evident that, since 1986, there has been a substantial increase in the area of south-eastern Wales which has a background level in excess of 10 ppb NO(2) and a notable reduction in land area with concentrations below 6 ppb NO(2) as an annual mean concentration. The possible future impact of increasing rural concentrations of NO(2) on Welsh vegetation is discussed with references to estimates of critical levels of NO(2) for adverse effects on plants.     

Elemental carbon (EC) and black carbon (BC) measurements with a thermal method and an aethalometer at the high-alpine research station Jungfraujoch

A thermal method for the determination of ambient organic carbon (OC) and elemental carbon (EC) concentrations in carbonaceous samples was further developed. Possible artifacts were investigated and were shown to be low. Good agreement of EC data with the German VDI reference method was found and detection limits were 1.3 μg for EC and 1.8 μg for OC. The method was applied to samples obtained with an aethalometer from an ongoing campaign at the high-alpine research station Jungfraujoch from July 1995 to June 1997. Measurements of EC concentration were used to derive a new site-specific calibration factor (instrumental absorption efficiency α_API) for the determination of the black carbon (BC) concentration. Despite a distinct seasonal cycle in BC, of around one order in magnitude with a maximum in summer and minimum in winter, α_API exhibited no significant seasonality. The derived calibration factor for the Jungfraujoch, α_API=9.3±0.4 m² g^-1, is lower than the manufacturer calibration by a factor ∼2. The results confirm the observation that the aethalometer determined BC concentration, underestimates the true value at remote sites, when the manufacturer calibration is used.     

HCHs and DDTs in sediment-dwelling animals from the Yangtze Estuary, China

HCHs and DDTs in sediment-dwelling animals including mollusks and crabs from the Yangtze Estuary were determined by GC-ECD. Levels of t-HCH were in the range of 1.2-5.5 ng g(-1) and averaged 3.5 ng g(-1) in mollusks, while t-DDT concentrations ranged from 26.0 to 68.8 ng g(-1), with a mean of 34.5 ng g(-1). In crabs t-HCH concentrations varied from 2.0 to 25.7 ng g(-1) and averaged 13.8 ng g(-1), whereas the concentrations of t-DDT were in the range of 1.5-24.8 ng g(-1) with a mean value of 5.9 ng g(-1). The HCHs and DDTs levels depend on geographical position and sources, showing the high levels at fresh water area in the estuary, such as XP, CM and LHK sites, and lower at brackish water area, such as FX site, and little difference between species. Results also indicate there was no significant relationship between t-HCH (t-DDT) concentrations and lipid contents both in mollusks and crabs because of non-equilibrium state under a specific estuarine dynamics; smaller individuals accumulated more HCHs and DDTs than larger individuals of mollusks at LHK site, showing different uptake rate for these pesticides; moreover, HCHs and DDTs levels were lower in female crab bodies than male crab bodies suggesting that the release of spawning. BSAFs (Biota- Sediment Accumulation Factors) from sediment-dwelling animals for HCHs and DDTs show a significant "one high with two low" and "one low with two high" effect in the Yangtze Estuary.     

Effects of nematicides on population of pratylenchus penetrans and growth of flue‐cured tobacco

Abstract

Field studies were conducted on loamy sand at Tamscu farm, Delhi, Ontario, to compare the spring ridge application of Telone C17 at 73 and 101L/ha, Vorlex at 28 and 84L/ha, Vorlex CP at 50L/ha, and spring rotovated application of oxamyl at 2.24kg/ha respectively for the control of Pratylenchus penetrans (Cobb) Filip. and Stek., and for effects on the yield and quality of fluecured tobacco. Experiments were conducted on May 9 in an area that had been summer fallowed in previous year. Nematode densities of P. penetrans per kilogram of soil were lower than other treatments and controls with Telone C17 at 73 L/ha treated plots on May 24; with Vorlex at 28 L on June 7; Vorlex at 84 L on May 24 and on June 7; Vorlex CP on June 7, and with oxamyl on Sept. 6. The nematode population counts per gram dry weight of root were lower with Telone C17 at 73 L/ha on June 7, July 5, and at 101 L/ha on July 5; with Vorlex at 28 L/ha on June 7, July 5, and Sept. 6; with Vorlex at 84 L/ha on June 7, June 21, July 5 and Sept. 6, and with Vorlex CP at 50 L/ha on June 7, July 5 and Sept. 6 in the ridged soil. The population was lower with oxamyl on June 21, July 5, and Sept. 6 in the rotovated soils. There was no difference in the agronomic data on yield, indices of grade, crop and maturity, while tobacco plant height and dry weight in the ridged fanning were greater with treatments of Vorlex at 84 L and Vorlex CP at 50 L/ha. The ridged farming had greater yield of tobacco than rotovated farming. Vorlex was the most effective of all nematicides used in the experiment.     

Illicit psychotropic substance contents in the air of Italy

Two in-field campaigns were performed in 2009 to elucidate the contents of illicit psychotropic substances in airborne particulates of Italian cities. Twenty-eight localities of eight Italian regions were investigated in winter, and further eleven sites in June (14 regions in total), thanks to contribution of Regional Environmental Agencies. Cocaine was found almost everywhere, although some sites were rural or suburban. The maximum was recorded in Milan in winter (～0.39 ng m^?3), and “high” values (up to ～0.16 ng m^?3) in other Northern cities and in Rome. Besides cocaine, three cannabinoids will be monitored, namely Δ⁹-tetrahydrocannabinol, cannabidiol and cannabinol. The three compounds often affected the air at lower extents than cocaine, and sometimes resulted absent. Cannabinol accounted for up to 90% of the total. The concentrations of illicit compounds were up to six times lower in June than in winter. This decrease was probably induced by the lowering of boundary layer height typical of winter, and by the oxidizing capacity of atmosphere, which is stronger in the warm season. Compared to n-alkanes, polynuclear aromatic compounds, nicotine, caffeine and airborne particulate, cocaine seemed to follow a peculiar behaviour; in fact, meaningful (≥0.80) Pearson (linear) regression coefficients were calculated from the corresponding concentrations only at local scale (e.g. Rome), and within just one season. Improvements of the method are needed to monitor illicit drug metabolites (e.g. benzoylecgonine, ecgonine methyl ester, 9-carboxy-11-nor-Δ⁹-tetrahydrocannabinol), heroin and semi-volatile amphetamines.     

Contamination of fish by 2,3,7,8-tetrachlorodibenzo-P-dioxin: A survey of fish from major watersheds in the United States

A survey of contamination of fish from major watersheds in the United States by 2,3,7,8-TCDD has been conducted by the U.S. EPA. Bottom feeding and predator fish were collected at 90 statistically selected and 305 regionally selected sites and analyzed by GC/MS. It was found that 19% of the statistically sampled sites and 31% of the regionally selected sites were contaminated at or above a minimum level of detection varying from 0.5 to 2.0 pg/g. Ten percent of all samples were contaminated at levels greater than 5.0 pg/g. It was also observed that a subset of samples collected at sites near discharge from pulp/paper manufacture (N=28) had a higher frequency of TCDD contamination above 5.0 pg/g (38%). This subset of samples also contained the sample of the greatest level of TCDD contamination (85 pg/g).     

Nitrate and nitric acid concentrations at two Rocky Mountain baseline monitoring sites

A two-tiered, Teflon/nylon filterpack system was used to characterize spatial and temporal patterns of particulate nitrates and nitric acid vapors at two monitoring sites in the Rocky Mountains. Geometric means for particulate nitrates were 38.9 and 52.8 ng/m(3) for the upper and lower sites, respectively. For nitric acid, geometric means of 70.4 ng/m(3) for the upper site and 295 ng/m(3) for the lower site were observed. The relatively low concentrations found at these two sites are comparable to published values for these materials at other remote sites. Atmospheric concentrations of nitrates and nitric acid were correlated significantly at each site, and the total nitrate concentrations (NO(3)(-) plus HNO(3)) were correlated between sites. Comparisons between the two sites indicate that nitric acid concentrations were statistically greater at the lower elevation site, whereas nitrate concentrations were not significantly different. No general seasonal or annual pattern of nitrate or nitric acid concentrations were evident when comparable sampling periods were examined.     

Bioaccumulation and effects of perfluorinated compounds (PFCs) in zebra mussels (Dreissena polymorpha)

Perfluorinated chemicals (PFCs) have been used for many years in numerous industrial products and are known to accumulate in organisms. A recent survey showed that tissue levels of PFCs in aquatic organisms varied among compounds and species being undetected in freshwater zebra mussels Dreissena polymorpha. Here we studied the bioaccumulation kinetics and effects of two major PFCs, perfluorooctane sulfonic acid compound (PFOS) and perfluorooctanoic acid (PFOA), in multixenobiotic transporter activity (MXR) and filtration and oxygen consumption rates in zebra mussel exposed to a range of concentrations of a PCF mixture (1–1,000 μg/L) during 10 days. Results indicate a low potential of the studied PFCs to bioaccumulate in zebra mussel tissues. PFCs altered mussel MXR transporter activity being inhibited at day 1 but not at day 10. Bioaccumulation kinetics of PFCs were inversely related with MXR transporter activity above 9 ng/g wet weight and unrelated at tissue concentration lower than 2 ng/g wet weight suggesting that at high tissue concentrations, these type of compounds may be effluxed out by MXR transporters and as a result have a low potential to be bioaccumulated in zebra mussels. Oxygen consumption rates but not filtering rates were increased in all exposure levels and periods indicating that at environmental relevant concentrations of 1 μg/L, the studied PFCs enhanced oxidative metabolism of mussels. Overall, the results obtained in this study confirm previous findings in the field indicating that an important fraction of PFC accumulated in mussel tissues is eliminated actively by MXR transporters or other processes that are metabolically costly.     

A field study of the ecotoxicology of copper to bryophytes

The impact of particulate copper, emitted from a copper rod-rolling plant, on the distribution of common grassland bryophytes has been investigated. Several areas of managed grassland, differing in total and water-extractable soil copper content, surrounding the factory were surveyed to establish species composition and distribution of the bryophyte flora. Clear differences emerged in the distribution patterns of the main acrocarpous (upright/tufted growth form) and pleurocarpous (horizontal/spreading growth form) species present, with some species being more or less confined to soils with elevated copper (Pohlia nutans), whilst others were absent from such sites. The distribution of acrocarpous species was not related to increasing soil copper concentrations, whereas pleurocarpous species showed considerable sensitivity. This may not be a simple reflection of sensitivity to copper; ecological factors such as differences in patterns of water and soluble copper uptake between the different growth forms may be significant factors, as may be changes in the vascular plant flora giving rise to differences in population densities of potential competitors between sites. Pleurocarpous species are absent from grassland where total soil copper >550 microg g(-1) dry weight, whilst the less sensitive acrocarpous species occur at total soil copper levels in excess of 2000 microg g(-1) dry weight.     

Mercury accumulation and tissue-specific antioxidant efficiency in the wild European sea bass (Dicentrarchus labrax) with emphasis on seasonality

The main goal of this study was to assess both mercury (Hg) accumulation and organs’ specific oxidative stress responses of gills, liver and kidney of Dicentrarchus labrax with emphasis on seasonality. Fish were collected in cold and warm periods in three stations: reference, moderated and highly contaminated sites. Our results showed that seasonal factors slightly influenced Hg accumulation between year periods (cold and warm) and strongly affected organs’ response basal levels. In contrast, seasonality seemed not to influence oxidative stress responses, since similar response patterns were obtained for both year periods, and moderate degree of antioxidant responses was obtained. Moreover, the oxidative stress profile may be attributed to Hg contamination degree, which showed organ-specific response and accumulation patterns. Hence, gills showed to be able to adapt to Hg contamination, and in opposition, kidney and liver demonstrated some vulnerability to Hg toxicity. The critical Hg concentrations indicated specific threshold limits for each organ. Overall, seasonality should be taken into account in monitoring programmes, helping to characterize the individuals’ reference values of response and thus to discriminate between the effects induced by natural causes or by contamination.