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The shallow-water hydrothermal vent system of Kueishan Island has been described as one of the world's most acidic and sulfide-rich marine habitats. The only recorded metazoan species living in the direct vicinity of the vents is Xenograpsus testudinatus, a brachyuran crab endemic to marine sulfide-rich vent systems. Despite the toxicity of hydrogen sulfide, X. testudinatus occupies an ecological niche in a sulfide-rich habitat, with the underlying detoxification mechanism remaining unknown. Using laboratory and field-based experiments, we characterized the gills of X. testudinatus that are the major site of sulfide detoxification. Here sulfide is oxidized to thiosulfate or bound to hypotaurine to generate the less toxic thiotaurine. Biochemical and molecular analyses demonstrated that the accumulation of thiosulfate and hypotaurine is mediated by the sodium-independent sulfate anion transporter (SLC26A11) and taurine transporter (Taut), which are expressed in gill epithelia. Histological and metagenomic analyses of gill tissues demonstrated a distinct bacterial signature dominated by Epsilonproteobacteria. Our results suggest that thiotaurine synthesized in gills is used by sulfide-oxidizing endo-symbiotic bacteria, creating an effective sulfide-buffering system. This work identified physiological mechanisms involving host-microbe interactions that support life of a metazoan in one of the most extreme environments on our planet. [ABSTRACT FROM AUTHOR]

Ambient bioaerosols are ubiquitous in the daily environment and can affect health in various ways. However, few studies have been conducted to comprehensively evaluate personal bioaerosol exposure in occupational and indoor environments because of the complex composition of bioaerosols and the lack of standardized sampling/analysis methods. We conducted a study to determine the most efficient collection/analysis method for the personal exposure assessment of multiple bioaerosols. The sampling efficiencies of three filters and four samplers were compared. According to our results, polycarbonate (PC) filters had the highest relative efficiency, particularly for bacteria. Side-by-side sampling was conducted to evaluate the three filter samplers (with PC filters) and the NIOSH Personal Bioaerosol Cyclone Sampler. According to the results, the Button Aerosol Sampler and the IOM Inhalable Dust Sampler had the highest relative efficiencies for fungi and bacteria, followed by the NIOSH sampler. Personal sampling was performed in a pig farm to assess occupational bioaerosol exposure and to evaluate the sampling/analysis methods. The Button and IOM samplers yielded a similar performance for personal bioaerosol sampling at the pig farm. However, the Button sampler is more likely to be clogged at high airborne dust concentrations because of its higher flow rate (4 L/min). Therefore, the IOM sampler is a more appropriate choice for performing personal sampling in environments with high dust levels. In summary, the Button and IOM samplers with PC filters are efficient sampling/analysis methods for the personal exposure assessment of multiple bioaerosols. [ABSTRACT FROM AUTHOR]

Background: The association between indoor air pollution and heart rate variability (HRV) has been well-documented. Little is known about effects of household activities on indoor air quality and HRV alteration. To investigate changes in HRV associated with changes in personal exposure to household particulate matter (PM) and household activities. Methods: We performed 24-h continuous monitoring of electrocardiography and measured household PM exposure among 50 housewives. The outcome variables were log10-transformed standard deviation of normal-to-normal (NN) intervals (SDNN) and the square root of the mean of the sum of the squares of differences between adjacent NN intervals (r-MSSD). Household PM was measured as the mass concentration of PM with an aerodynamic diameter <2.5 µm (PM2.5). We used mixed-effects models to examine the association between household PM2.5 exposure and log10-transformed HRV indices. Results: After controlling for potential confounders, an interquartile range change in household PM2.5 with 1- to 4-h mean was associated with 1.25–4.31% decreases in SDNN and 0.12–3.71% decreases in r-MSSD. Stir-frying, cleaning with detergent and burning incense may increase household PM2.5 concentrations and modify the effects of household PM2.5 on HRV indices among housewives. Conclusions: Indoor PM2.5 exposures were associated with decreased SDNN and r-MSSD among housewives, especially during stir-frying, cleaning with detergent and burning incense. [ABSTRACT FROM AUTHOR]

Pollutant concentrations detected in oysters from 12 different culture areas of Taiwan (especially for the Hsiangshan area and the Machu Islands) from 1991/98 were evaluated to investigate potential carcinogenic (inorganic As and organochlorine pesticides) and non-carcinogenic (Cu, Zn, Cd and inorganic As) risk to the public from ingestion ofthe oysters. The highest geometric mean (GM) Cu and Zn concentrations of 1108 (range 113/2806) and 1567 (range 303/3593) mug/g dry weightwere obtained in oysters from the Hsiangshan coastal area. The maximum GM Cd and As concentrations of 6.82 and 19.3 mug/g dry weight werefound in oysters from the Machu Islands area. The p,p'-DDE values range from not detectable in Penghu Islands' oysters to 164 ng/g dry weight in Machu Islands' oysters. The highest tDDT (sum of p,p'-DDE, p,p'-DDD and p,p'-DDT) concentrations of 337 and 340 ng/g dry weight were found in oysters from Kimmen and Machu Islands, respectively. A calculated target hazard quotient (THQ; daily intake/reference dose) of11.4 (based on 139 g oysters/day) for Cu caused by consuming oystersfrom the Hsiangshan area is higher than that from other areas (range0.124/5.95). The highest average Cu intake from Hsiangshan's oystersfor individuals is 11.4 times (i.e. THQ=11.4) more than that of reference dose (40 mug/kg/day). However, the maximum THQ values for Cd and As caused by consuming oysters collected from the Machu Islands were 5.57 and 2.63 for Cd and As, respectively. Generally, the results of THQ showed that if only the maximally exposed individuals were considered, the value of 65.4% for oyster was higher than 1.0 in comparison with reference dose. All cancer risk estimates for inorganic As from consuming oysters were higher than 10-6 (range from 128x 10-6 to 509x 10-6 for maximally exposed individuals and range from 17.1x 10-6 to 68.0x 10-6 for typically exposed individuals, respectively); that is the risk ofthe low [ABSTRACT FROM AUTHOR]

Pig farming is a major industry in southern Taiwan, with two million pigs being raised along the banks of the Kaoping River. Excretions from pigs are discharged into the river and carried into the sea. In this study, 24 surface sediments and 1 sediment core off southwestern Taiwan were analyzed to determine, quantitatively, the extent of coprostanol addition and its distribution, and to obtain the input of coprostanol over the past. Geographically, the percent of coprostanol is highest around the river mouth, and decreases to about 1&percnt; at the shelf break and close to 0 at 40 nautical miles from the river mouth. The progressive seaward decline of the percent of coprostanol from the river mouth can be attributed to dilution of coprostanol by uncontaminated sediment and&sol;or sediment containing lower levels of coprostanol, dilution of coprostanol by biogenic sterols, and degradation of coprostanol. Kaoping Canyon sediments contain a high percent of coprostanol, which can be attributed to a direct input of river sediments, canyon currents being alternate up canyon and down canyon, and the blocking effect of a high topographic. [ABSTRACT FROM AUTHOR]