Some flame retardants and the antimicrobials triclosan and triclocarban enhance the androgenic activity in vitro

Contaminants including flame retardants, antimicrobial agents and phthalates, occurring as residues in human tissues were associated with altered endocrine function. In our study we analysed the flame retardants tetrabromobisphenol A (TBBPA), hexabromocyclodecane (HBCD), penta-bromodiphenylether (BDE-100) and hexa-BDE (BDE-155), the antimicrobial compounds triclosan (TCS) and triclocarban (TCC) and eight phthalates for their androgenic and antiandrogenic activity in vitro in the MDA-kb2 cell line. No or only weak androgenic activity was observed for all the tested compounds. TBBPA showed weak antiandrogenic activity, which was demonstrated for the first time. The flame retardants HBCD, BDE-100 and BDE-155 enhanced the dihydrotestosterone-dependent activation of androgen receptor-responsive gene expression but exhibited little or no agonistic activity. The enhancement reached 150%, which was similar to the antimicrobials (TCS up to 180%, and TCC up to 130%). This enhancement of androgenic activity represents a novel mode of action of the endocrine activity of flame retardants. In contrast, most phthalates showed antiandrogenic activity. Butylbenzyl phthalate (BBP), dibutyl phthalate (DBP) and diethyl phthalate (DEP) showed strong antiandrogenicity, whereas the action of diethylhexyl phthalate (DEHP), dipentyl phthalate (DPP), dimethyl phthalate (DMP), and the DEHP metabolite monoethylhexyl phthalate (MEHP) was lower. Our in vitro study demonstrates for the first time a weak antiandrogenic activity of TBBPA, and a significant enhancement of the androgenic activity of HBCD, BDE-100 and BDE-155, which represents a novel mechanism of hormonal activity of flame retardants.     

Photolysis of polycyclic aromatic hydrocarbons adsorbed on spruce [Picea abies (L) Karst] needles under sunlight irradiation

Photolysis of polycyclic aromatic hydrocarbons (PAHs) sorbed on surfaces of spruce [Picea abies (L.) Karst.] needles under sunlight irradiation was investigated. PAHs were produced by combustion of polyvinyl chloride (PVC), wood, high-density polyethylene (HDPE), and styrene in a stove. The factors of sunlight irradiation on the surfaces of spruce needles were taken into consideration when investigating the kinetic parameters. The photolysis of the 18 PAHs under study follows first-order kinetics. The photolysis half-lives range from 15 h for dibenzo(a,h)anthracene to 75 h for phenanthrene. Photolysis of some PAHs on surfaces of spruce needles may play an important role on the fate of PAHs in the environment.     

Dioxins, dioxin-like PCBs and chloroorganic contaminants in herring, Clupea harengus, from different fishing grounds of the Baltic Sea

The contaminant levels of dioxins, dioxin-like PCBs and a range of chloroorganic compounds have been determined in relation to various fishing grounds of the Baltic Sea. Sampling covered an area from the Skagerrak to the coast of Latvia. The data are compared with herring from fishing grounds in the North Sea and west of the British Isles. Also the temporal trend of the dioxin levels in the edible part of herring landed around the Island of Rügen is given from commercial samples collected between 1996 and 2004. A continuous increase of the dioxin concentrations was observed from west to east. Lowest concentrations of 0.199 ng WHO-PCDD/F-TEQ kg(-1)wet weight were found in herring fillets west of the British Isles. Highest level of 6.972 ng WHO-PCCD/F-TEQ kg(-1)w.w. was analysed in fillets off the coast of Latvia. Results showed also a spatial dependence of the WHO-TEQ ratio dioxins:dioxin-like PCBs and of the dioxin congener profile. Only the DDT group of various chloroorganic compounds determined, showed a dependence from the fishing ground. A clear temporal tendency could not be deduced from the data.     

Dilution-based emissions sampling from stationary sources: Part 1--Compact sampler methodology and performance

This paper presents the design and performance of a compact dilution sampler (CDS) for characterizing fine particle emissions from stationary sources. The sampler is described, along with the methodology adopted for its use. Dilution sampling has a number of advantages, including source emissions that are measured under conditions simulating stack gas entry and mixing in the ambient atmosphere. This is particularly important for characterizing the semivolatile species in effluents as a part of particulate emissions. The CDS characteristics and performance are given, along with sampling methodology. The CDS was compared with a reference dilution sampler. The results indicate that the two designs are comparable for tests on gas-fired units and a diesel electrical generator. The performance data indicate that lower detection limits can be achieved relative to current regulatory methods for particulate emissions. Test data for the fine particulate matter (PM2.5) emissions are provided for comparison with U.S. Environment Protection Agency (EPA) Conditional Test Method 040 for filterable particulate matter (FPM) and the EPA Method 202 for condensable particulate matter. This comparison showed important differences between methods, depending on whether a comparison is done between in situ FPM determinations or the sum of such values with condensable PM from liquid filled impingers chilled in an ice bath. These differences are interpretable in the light of semivolatile material present in the stack effluent and, in some cases, differences in detection and quantification limits. Determination of emissions from combustors using liquid fuels can be readily achieved using 1-hr sampling with the CDS. Emissions from gasfired combustors are very low, requiring careful attention to sample volumes. Sampling volumes corresponding with 6-hr operation were used for the combined mass and broad chemical speciation. Particular attention to dilution sampler operation with clean dilution air also is essential for gas-fired sources.     

Reducing Indoor Air Formaldehyde Concentrations

Urea-formaldehyde resin bonded partlcleboard, medium density fiberboard and plywood paneling are used as flooring, wall paneling, for cabinet work and in furniture, and are present In almost every office, home and public building. If large quantities of these products are used In poorly ventilated spaces, high manufacturing quality control is necessary to avoid problems of latent formaldehyde release. Indoor air formaldehyde concentrations depend on the nature of the product, the product surface to air volume (loading) factor, temperature, humidity, age and product emission rates. Standard test methods are now available for measuring product emission rates that make It possible to predict the performance of UF-bonded pressed wood materials If use conditions and environmental parameters are known. Recent modifications In adhesive and board manufacturing parameters have made It possible to reduce formaldehyde emission significantly, and UF-bonded wood products are now capable of meeting indoor air quality standard levels of 0.1 ppm under almost all customary loading conditions.     

Identifying conservation priorities for threatened Eastern Himalayan mammals

To augment mammal conservation in the Eastern Himalayan region, we assessed the resident 255 terrestrial mammal species and identified the 50 most threatened species based on conservation status, endemism, range size, and evolutionary distinctiveness. By using the spatial analysis package letsR and the complementarity core‐area method in the conservation planning software Zonation, we assessed the current efficacy of their protection and identified priority conservation areas by comparing protected areas (PAs), land cover, and global ecoregion 2017 maps at a 100 × 100 m spatial scale. The 50 species that were most threatened, geographically restricted, and evolutionarily distinct faced a greater extinction risk than globally nonthreatened and wide‐ranging species and species with several close relatives. Small, medium‐sized, and data‐deficient species faced extinction from inadequate protection in PAs relative to wide‐ranging charismatic species. There was a mismatch between current PA distribution and priority areas for conservation of the 50 most endangered species. To protect these species, the skewed regional PA distribution would require expansion. Where possible, new PAs and transboundary reserves in the 35 priority areas we identified should be established. There are adequate remaining natural areas in which to expand current Eastern Himalayan PAs. Consolidation and expansion of PAs in the EH requires strengthening national and regional transboundary collaboration, formulating comprehensive regional land‐use plans, diversifying conservation funding, and enhancing information sharing through a consolidated regional database.     

Concentrations and accumulation profiles of polychlorinated dibenzo-p-dioxins and dibenzofurans in aquatic tissues, and ambient air from South Korea

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/DFs), including 2378-substituted isomers were present in samples of shellfish and fish, and ambient air collected from Masan Bay, and Masan City, South Korea. Total concentrations of PCDDs/DFs in mussel and clam were 750 pg g(-1), lipid weight (lw), and 3418 pg g(-1), lw, respectively. Total concentrations of PCDDs/DFs in mullet, gizzard and flounder were 52, 82, and 122 pg g(-1), lw, respectively. Shellfish tissues contained a greater number of PCDD/DF isomers, contributing greater total concentrations of PCDDs/DFs compared to fish collected from the same locations. The predominance of 2378-substituted PCDDs/DFs in fish is represented in greater total concentrations of 2378-TeCDD equivalents (TEQs), whereas there was very limited occurrence of 2378-substituted isomers in shellfish. TEQ concentrations in samples of mussel and clam were 0.97 and 12 pg g(-1), lw, respectively. Total TEQs in mullet, gizzard and flounder were 12, 22 and 18 pg g(-1), lw, respectively. In fish 2378-substituted PCDDs accounted for 100% of the total concentrations of PCDDs, and 2378-substituted PCDFs accounted from 59% to 73% of the total PCDFs. The 2378-substituted isomers accounted for only 3% of the total PCDDs/DFs in shellfish. Ambient air collected from two sites contained a wide range of isomers of tetra- through heptachlorinated PCDDs/DFs. Even though the total concentration of PCDDs/DFs in ambient air (12.8 pgm(-3)) collected from an industrial area was 2-fold greater than that in air samples (6.3 pgm(-3)) collected from an urban/rural area, total TEQs (0.07 and 0.08 pgm(-3)) there was no statistical difference between the two samples.     

ALGAL BLOOM PROBABILITY IN A LARGE SUBTROPICAL LAKE1

ABSTRACT: Algal blooms, defined as chlorophyll α concentrations greater than 40 μg l^?1, are common in Lake Okeechobee, Florida. Using logistic regression techniques, we have developed equations that relate limnological variables to algal bloom occurrence in four distinct open-water regions of this large shallow lake: central pelagic, northwest, southwest, and a transition region between the western and pelagic regions. Wind velocity and total phosphorus, which are closely related to resuspended material in the central region, are negatively related to algal bloom occurrence there. In the transition region, algal bloom occurrence is positively related to total nitrogen and wind velocity. Algal bloom occurrence is strongly and positively related to total nitrogen and total phosphorus concentrations in the western regions. The logistic regression model predicts an algal bloom probability greater than 95 percent in the northwest region when total phosphorus exceeds 0.10 mg l^?1 and total nitrogen exceeds 2.5 mg l^?1. In the southwest region the model predicts algal bloom probability of 100 percent when total phosphorus exceeds 0.10 mg l^?1 and total nitrogen exceeds 2.8 mg l^?1. Given 1994 mean total phosphorus concentrations of 0.05 and 0.04 mg l^?1 in the northwest and southwest regions, respectively, total nitrogen would have to remain below 1.32 and 1.43 mg l^?1, respectively, to keep the algal bloom probability below 10 percent. Because the lake is heterogenous, such nutrient standards should be considered on an in-lake regional basis for Lake Okeechobee.