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In this study, we determined the concentrations of polycyclic aromatic hydrocarbons (PAHs) in road dust from Myanmar, Japan, Taiwan, and Vietnam. PAHs were detected in urban and rural areas of Myanmar at mean concentrations of 630 ng/g dry weight and 200 ng/g dry weight, respectively. PAHs were also detected in road dust from Vietnam (mean 1700 ng/g) and Taiwan (2400 ng/g). PAH diagnostic ratios suggested that fossil fuel vehicular exhaust and biomass combustion are major sources of PAHs in road dust in Myanmar. Road dust samples from Japan, Taiwan, and Vietnam had similar PAH diagnostic ratios, implying that PAH sources are similar. We assessed the human health risks posed by PAHs in road dust using carcinogenic equivalents (CEQs) and incremental lifetime cancer risk (ILCR). Mean CEQs were decreased in the order Taiwan (173 ng/g) > Vietnam (162 ng/g for Hanoi) > Myanmar (42 and 31 ng/g for Yangon and Pathein, respectively) > Japan (30 ng/g for Kumamoto). Benz[a]pyrene, fluoranthene, and benzo[b]fluoranthene, the predominant PAHs, contributed > 70% of total CEQs. High ILCR values were found for Taiwan (5.9 × 10−4 and 9.9 × 10−4 for children and adults, respectively) and Vietnam (6.5 × 10−4 and 9.2 × 10−4 for children and adults, respectively, in Hanoi), indicating that PAHs in road dust pose cancer risks to the inhabitants of Taiwan and Hanoi. To our knowledge, this is the first report to identify PAH pollution in the environment and to evaluate the human health risks of these PAHs in Myanmar. [ABSTRACT FROM AUTHOR]

To investigate the early life history of Seriola dumerili, we first validated otolith daily increments using reared fish (11-51 days after hatching). Four larval and early-juvenile S. dumerili were collected in May and July 2015 around the Penghu Islands, Taiwan (23.45-23.70 °N, 119.40-119.70 °E), by surface larval net towing, but not from drifting seaweeds. Seriola dumerili were caught at the thermal front, and the total lengths and ages ranged 7.4-42.5 mm and 18-56 days, respectively. Our results indicate that the hatching dates of S. dumerili were April to June and larvae may have been accumulated in the frontal zone before the juvenile phase. [ABSTRACT FROM AUTHOR]

The sampling efficiency of two types of beam trawl towed at different velocities was compared when sampling deep-sea demersal fish and decapod crustaceans. The trawls were a Sigsbee-Agassiz type of 2 m span, and an Oregon type of 3 m span. The different hauls caught by the Oregon type beam trawl of 3 m span towed at 1.5 knot (3m 1.5 kt), the Oregon type towed at 0.8 knot (3m 0.8 kt) and the Sigsbee-Agassiz type towed at 1.5 knot (2m 1.5 kt) were compared by analysis of variance (ANOVA), the Tukey test, cluster analysis based on Morisita-Horn index, and correspondence analysis. The minimum viable sample size was determined by a randomization test. For demersal fish, the type of gear used had more influenced on the samples obtained than the towing velocity. For decapod crustaceans, no significant difference was detected between different trawls towed at different velocities. The common idea that if these types of trawl are towed at 1 knot or more, they cannot efficiently sample epifauna, but demersal fish can be well sampled, should be abandoned. The samples of demersal fish caught by 3m 1.5 kt revealed the greatest consistency and lowest variation than the others. We recommend using an Oregon type beam trawl of 3 m span towed at 1.5 knot as an ordinary deep-sea sampling device. Only a single successful haul or a sample size of 52 individuals was sufficient for estimating demersal fish diversity, but at least two successful hauls or a sample size of 54 individuals were needed for decapod crustaceans. If possible, seven successful hauls or a sample size of 189 individuals of decapod crustaceans are recommended for community study. [ABSTRACT FROM AUTHOR]