Levels of polybrominated diphenyl ethers (PBDEs) in breast milk from central Taiwan and their relation to infant birth outcome and maternal menstruation effects

In utero exposure to polybrominated diphenyl ethers (PBDEs) reduces the number of ovarian follicles in rat females and causes permanent effects on rat males. Little data have been gathered on the associations between PBDEs exposure and birth outcome and female menstruation characteristics in both epidemiological and animal studies. The aim of this study was to examine how PBDEs in breast milk are associated with infant birth outcome and maternal menstruation characteristics. Study participants were healthy women recruited from central Taiwan between December 2000 and November 2001. Twelve congener levels of PBDEs (BDE-17, 28, 47, 66, 85, 99, 100, 138, 153, 154, 183, 209) in 20 breast milk samples were measured by gas chromatography with high resolution mass spectrometer. The mean level of PBDEs in breast milk was 3.93+/-1.74 ng/g lipid. The estimated PBDE daily intake for a breastfed infant was 20.6 ng/kg b.w./day after delivery. After maternal age, pre-pregnant BMI, and parity were adjusted, increased PBDEs in breast milk was related with decreased birth outcome, particularly for birth weight and length, chest circumference, and Quetelet's index of infants. No significant differences in PBDEs were found between the two groups of menstrual cycle length higher and lower than 30 days after we adjusted for maternal age, pre-pregnant BMI, and parity. In utero exposure to low doses of PBDEs may result in lower birth weight and short or birth length. Our findings are limited based on the low doses of PBDEs and the small sampling size.     

Waterborne cues from crabs induce thicker skeletons, smaller gonads and size-specific changes in growth rate in sea urchins

Indirect predator-induced effects on growth, morphology and reproduction have been extensively studied in marine invertebrates but usually without consideration of size-specific effects and not at all in post-metamorphic echinoids. Urchins are an unusually good system, in which, to study size effects because individuals of various ages within one species span four orders of magnitude in weight while retaining a nearly isometric morphology. We tracked growth of urchins, Strongylocentrotus droebachiensis (0.013–161.385 g), in the presence or absence of waterborne cues from predatory Jonah crabs, Cancer borealis. We ran experiments at ambient temperatures, once for 4 weeks during summer and again, with a second set of urchins, for 22 weeks over winter. We used a scaled, cube-root transformation of weight for measuring size more precisely and for equalizing variance across sizes. Growth rate of the smallest urchins (summer: <17 mm diameter; winter: <7 mm diameter) decreased by 40–42% in response to crab cues. In contrast, growth rate of larger urchins was unaffected in the summer and increased in response to crab scent by 7% in the winter. At the end of the 22-week experiment, additional gonadal and skeletal variables were measured. Cue-exposed urchins developed heavier, thicker skeletons and smaller gonads, but no differences in spine length or jaw size. The differences depended on urchin size, suggesting that there are size-specific shifts in gonadal and somatic investment in urchins.     

Growth and reproduction in the Antarctic brooding bivalve Adacnarca nitens (Philobryidae) from the Ross Sea

We present information on the reproductive biology, population structure, and growth of the brooding Antarctic bivalve Adacnarca nitens Pelseneer 1903, from the Ross Sea, Antarctica. Individuals ranging from 0.85 to 6.00 mm were found attached to a hydrozoan colony. This species shows low fecundity and large egg size, common to other brooding species. The minimum size at which oogenesis was detected was 2.3 mm and the minimum size at which brooding was evident was 3.9 mm. Embryos of a full range of developmental stages were brooded simultaneously in females. The population showed a log–normal distribution and results suggest non-periodic reproduction with continuous embryonic development. The reproductive traits of A. nitens are discussed in the context of circum-Antarctic species distribution and limitations to dispersal in brooding benthic invertebrates.     

Adoption and economic impacts of laser land leveling in the irrigated rice-wheat system in Haryana,India using endogenous switching regression

This study assesses the factors affecting the adoption of laser land leveling (LLL) and its impact on crop yields and net returns. It uses household survey data collected from 621 randomly selected farmers in Karnal District of Haryana, India, and applies endogenous switching regression models. Unbiased model results show that the adoption of LLL has significant positive impacts on yields (rice +549 kg ha⁻¹; wheat +471 kg ha⁻¹) and net returns (an aggregate increase of US$230/ha) in the rice-wheat production system, thereby raising farmers' income substantially. Our results show that LLL adoption at the farm level is influenced by land size and quality, tenure system, availability of farm machinery (tractor), access to finance and farm cooperatives, gender of household head, level of education and training and access to extension services. Therefore, LLL scaling strategies need to consider these bio-physical and socio-economic parameters to reach adoption at scale and generate large social, economic, and environmental benefits.     

Recovery of copper from small grain size fractions of municipal solid waste incineration bottom ash by means of density separation

Small grain size fractions of municipal solid waste incineration (MSWI) bottom ash (BA) contain elemental and chemically bonded metals in appreciable amounts, especially copper. Investigations with a centrifugal concentrator were carried out using samples, which had been treated with different impact devices. Partly the impacts of single devices were visible in outlines, but mostly the surfaces of the metals were still covered with mineral residues. To generate copper rich fractions, parameters of the separation process should ensure mass yields <2%, best between 0.5 and 1%. The density of the concentrates is then generally >3.2 g/cm³. Best results were achieved with material from a special treatment train which is adapted to grain sizes <2 mm. Reliable copper contents between 20 and 40% (single runs >50%) could be realised. However, considering the required mass yields, referred to this subset only 150–170 g copper would be recovered from 1 Mg MSWI BA. Furthermore, this copper is only in parts present in elemental form. A dependable added value of such treatment step seems to be given only, if that enables a recycling of the mineral aggregates (tailings) in parallel to avoid landfill costs.     

Organochlorine concentrations in franciscana dolphins, Pontoporia blainvillei, from Brazilian waters

Blubber samples were collected from ten franciscana dolphins either incidentally captured in fishing operations or stranded on São Paulo (SP) and Paraná (PR) states littoral, Southeastern and Southern Brazilian coast, respectively. Determination of PCB, DDT and HCB concentrations were performed by capillary gas chromatograph coupled to electron capture detector (ECD). ΣDDT, ΣPCB and HCB concentrations ranged from 264 ng g⁻¹ to 5811 ng g⁻¹ lipid, from 909 ng g⁻¹ to 5849 ng g⁻¹ lipid and from 10 ng g⁻¹ to 61 ng g⁻¹ lipid, respectively. Regarding DDTs, the distribution of the mean percentages decreased in the following order: p,p′-DDE > p,p′-DDD > p,p′-DDT. The ΣDDT/ΣPCB ratio varied between 0.27 and 0.42 in Northern and Central SP coast, while in Southern SP and PR coast the values were 1.6 and 1.9, respectively. Dissimilarities in ΣDDT/ΣPCB ratios point to different sources of organochlorine compounds to franciscana dolphins in the study area. Considering the endocrine disruptive action of organochlorine compounds, the concentrations found in franciscana dolphins from Brazilian waters may represent an additional obstacle to the conservation of this endangered cetacean species.     

Seasonal differences in mercury accumulation in Trichiurus lepturus (Cutlassfish) in relation to length and weight in a Northeast Brazilian estuary

Background, aim, and scope  At tropical latitudes, and especially on the semi-arid coasts of the Brazilian Northeast, the rainfall regime governs the water quality of estuaries due to the pronounced difference between the rainy and dry seasons. These changes may be responsible for seasonal changes in bioavailability of mercury (Hg) and other pollutants to the estuarine and coastal biota. Mercury bioaccumulates along estuarine–marine food chains usually result in higher concentrations in tissues of top predators and posing a risk to both marine mammals and humans alike. The Goiana River Estuary (7.5° S) is a typical estuary of the semi-arid tropical regions and supports traditional communities with fisheries (mollusks, fish, and crustacean). It is also responsible for an important part of the biological production of the adjacent coastal waters. Materials and methods   Trichiurus lepturus (Actinopterygii: Perciformes) is a pscivorous marine straggler. Fish from this species (n = 104) were captured in a trapping barrier used by the local traditional population and using an otter trawl net along the main channel of the low estuary during two dry seasons (D1 = November, December 2005, January 2006; D2 = November, December 2006, January 2007) and the end of a rainy season (R = August, September, October 2006). Fish muscle samples were preserved cold and then freeze-dried prior to analysis of its total mercury (Hg-T) contents. Total mercury was determined by cold vapor atomic absorption spectrometry (CV-AAS) with sodium borohydride as a reducing agent. Results  The studied individuals (n = 104) were sub-adult (30–70 cm, 71 ind.) and adult fish (>70 cm, 33 ind.). Weight (W) (204.1 ± 97.9 g, total biomass = 21,229.7 g) and total length (TL) (63.1 ± 10.1 cm, range 29.5–89.0 cm) presented a significant (p < 0.05) correlation. Two-way ANOVA (n = 81) showed that TL and W had significant differences (p < 0.05) among seasons, being higher in D1 than in D2 and R, respectively. Moreover, season vs. month interaction were detected for the variables length and weight. For the variable weight was detected significant difference for the factor month (p < 0.05). It suggests that the fish enter the estuary at the end of the rainy season and increase in length and weight during the time they spend in the estuary. Fish from this estuary are shown to be fit for human consumption (125.3 ± 61.9 μgHg-T kg^–1 w.wt.; n = 104). Fish mercury contents increased with size and weight. Correlations between TL and Hg-T (r = 0.37286) and between W and Hg-T (r = 0.38212) were significant (p < 0.05). Dryer months showed higher mercury concentrations in fish (D1 773.4 ± 207.5 μgHg-T kg^–1 d.wt., n = 27; D2 370.1 ± 78.8 μgHg-T kg^–1 d.wt., n = 27; R 331.2 ± 138.5 μgHg-T kg^–1 d.wt., n = 27). The variable mercury concentration showed differences in relation to the factor season (p < 0.05), where fish captured during the first dry season showed the highest concentration of mercury. The correlation between Hg-T and rainfall (Rf) showed a negative correlation (r = –0.56; p < 0.05). Discussion  The main likely source of mercury to this estuary is diffuse continental run off, including urban and industrial effluents. Since concentration of mercury in fish tissue is negatively correlated to rainfall, but positively correlated with fish length and weight, it suggests that fish growth in this estuary results in mercury uptake and concentration on the fish tissue. In the dry season of 2005–2006, when rainfall remained below the historic average, fish bioaccumulated significantly more mercury than in the dry season 2006–2007, when rainfall was within the predictable historic average. It is suggested that less rainfall, and consequently less particulate matter and less primary production in the estuary, make mercury more available to the higher levels of the estuarine food chain. In the case of higher rainfall, when river flow increases and water quality in the estuary is reduced, mercury probably is quickly exported associated to the particulate matter to the adjacent coastal waters where it then disperses. This species is a potential routine bioindicator for mercury contamination of the biota, but so far was used only with a limited number of individuals and contexts. Conclusions  Fish from the Goiana River estuary can still be safely consumed by the local population. However, any further contamination of this resource might lead to total mercury levels above the recommended limits for pregnant women and small children. The proposed heavy dependency of total mercury levels in fish on water quality indicates that land use and water quality standards must be more closely watched in order to guarantee that best possible practices are in place to prevent bioaccumulation of mercury and its transfer along the food chain. Human interventions and climatic events which affect river water flow are also playing a role in the mercury cycle at tropical semi-arid estuaries. Recommendations and perspectives   T. lepturus is largely consumed by coastal populations of tropical and sub-tropical countries all over the world. It is also consumed by a number of marine mammals over which we have a strong conservation interest. This species is also a link among different ecosystems along the estuarine ecocline. Therefore, knowledge of its degree of contamination might contribute to public health issues as well as marine conservation actions. Studies on mercury and other contaminants using this species as bioindicator (cosmopolitan, readily available) could help elucidating mechanisms through which pollutants are being transferred not only through the food chain, but also from estuarine–coastal–open waters. In addition, using the same species in marine pollution studies, especially as part of a mosaic of species, allows for wide range comparisons of marine food chain contamination.     

Limitations in the use of potassium dichromate as a blood preservative for the analysis of organohalogenated compounds: two month results

For analysis of organochlorine contaminants in human tissue, the "gold standard" for preservation, storage, and shipping is usually freezing. However, this method can be difficult, if samples are taken in remote areas, and costly, when the samples must be shipped on dry ice. Therefore, a more simple and cost effective method of preservation is essential for remote field work. Potassium dichromate (K(2)Cr(2)O(7)) has been successfully employed in the preservation of human and cows' milk as well as chicken eggs. Our previous studies described the use of potassium dichromate for preservation of whole blood for analysis of dioxins, dibenzofurans, and PCBs. Potassium dichromate was found to successfully preserve blood at room temperature for 34 d with no significant differences in the measured concentrations of chemical contaminants or blood lipid level when compared to frozen samples. However, in a follow-up study, 3 months and 6 months of potassium dichromate preservation proved inadequate to preserve the samples for organic pollutant analysis. We noted that the lipid portion of the blood in the chemically preserved samples was declining in level or degrading, while the persistent organic pollutants remained intact at the same levels on a whole weight basis. To narrow down the window of efficacy for the use of potassium dichromate to preserve blood samples for analysis, the present study compared chemical preservation to freezing for an intermediate time period, 2 months. Similar to our previous findings at 3 and 6 months, at 2 months significant lipid degradation was observed in the chemically preserved samples. Chemically preserved samples had significantly higher levels of organochlorine contaminants (dioxins, dibenzofurans, and PCBs) when measured on a blood lipid basis but not on a wet weight basis compared to frozen samples. While 2 months of potassium dichromate preservation was not useful for obtaining accurate measure of dioxins, furans, and PCBs on a lipid basis, previous studies found this method of preservation to be useful for at least one month (Schecter, A., Pavuk, M., P?pke, O., Malisch, R., 2004. The use of potassium dichromate and ethyl alcohol as blood preservatives for analysis of organochlorine contaminants. Chemosphere 57, 1-7). However blood stored at -70 degrees C and at 22 degrees C with potassium dichromate gave similar results when expressed on a wet weight basis.     

Residential and biological exposure assessment of chemicals from a wood treatment plant

This paper evaluates the results of contamination of residents and residential homes located in close proximity to a Wood Treatment Plant. The plant has produced treated wood products continuously since 1904. The principle chemicals used to treat the wood, which is primarily used for railroad ties (oblong objects laid perpendicular to the rails to act as a base for the tracks), are creosote and pentachlorophenol. For a number of years, the plant burned treated waste wood products containing creosote and pentachlorophenol. First the plant pressure impregnates the wood with creosote and pentachlorophenol, and then the wood is stacked on open ground to allow it to air dry. Chemicals from recently treated wood ties are allowed to evaporate into the air or drip onto the ground surrounding the stacked wood. Small drainage ditches carry the liquid wastes into larger water channels where eventually the waste streams are discharged into a river adjacent to the plant. The river serves as a source of drinking water for the nearby community. Prevailing wind patterns favor a drift of air emissions from the plant's boiler stack over the nearby community and its residents. Over the past few years, the town's residents have become increasingly concerned about their health status and have voiced concerns regarding multiple health problems (including cancer), possibly associated with plant discharges. The intention of this study is to examine a representative sample of the potentially affected residents and to evaluate their residential environment for the presence of dioxin and/or its congeners. Data obtained from EPA's Toxic Release Information (TRI) database revealed the plant routinely discharged creosote, pentachlorophenol, dioxin and dioxin-like compounds into the ambient air via fugitive air emissions and surface waste waters. Sampling of household dust and water sediment within and outside of residences within a 2-mile radius of the plant revealed the presence of significantly elevated levels of dioxins, principally octachlorodibenzo-p-dioxin (OCDD) and 1,2,3,4,6,7,8-hepta-CDD. Biomonitoring of 29 subjects identified the presence of significantly elevated chlorinated dioxins and furan levels (OCDD=1049 ppt for exposed and 374 ppt for controls and 1,2,3,4,6,7,8-hepta CDD=132 ppt for exposed and 45.1 ppt for controls). These levels are consistent with exposures to pentachlorophenol in this group of subjects. And they confirm the presence of unsafe levels of chlorinated dioxins in these persons.