There has been no experimental study demonstrating the effects of airborne Asian sand dust (AASD) on the male reproductive function. The organic substances adsorbed onto AASD collected from the atmosphere of Iki-island in Japan were excluded by heat treatment at 360 °C for 30 min. The effects of AASD or heated-AASD (H-AASD) towards the male reproductive function were compared to murine lungs to investigate the role of organic substances. ICR mice were intratracheally administrated two kinds of AASD four times at 2-week intervals. The daily sperm production (DSP/g testis) in the H-AASD-exposed mice decreased by 11.4% , while the AASD-exposed mice decreased by 17.7%. Exposure to AASD decreased the sperm motility, progressive motility, curvilinear velocity (VCL) , amplitude of lateral head displacement (ALH) and beat cross frequency (BCF) (18.9% , 28.4% , 21.0% , 18.9% and 21.0% vs. control) . However, there were no significant decreases in the H-AASD-exposed mice. These results suggest that the sperm production fertility was aggravated by the two types of AASD along with the aggravated sperm quality AASD. However, there were no aggravated effects of H-AASD on the sperm quality. These two results suggest that the particle aggravated sperm production and the organic substances adsorbed onto AASD aggravate the sperm quality.

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Ozone concentrations monitored at Japanese air pollution and acid deposition monitoring stations from 2005 through 2007 were assessed based on their 8-hour average, which is used in the assessment method of the United States Environmental Protection Agency (USEPA) standard and World Health Organization (WHO) guideline, in order to evaluate the Japanese photochemical ozone pollution. The assessed values at almost all the stations exceeded the WHO guideline, while 22 % of the stations met the USEPA standard. A grid average data analysis showed that about 11 % of the population lives in an area in which the ozone concentration met the USEPA standard. From a comparison with the USA and European countries based on the USEPA standard assessment, it was found that Japanese photochemical ozone pollution was more serious especially in the urban and suburban areas. To evaluate the ozone pollution in Japan, the annual maximum 8-hour average and/or annual maximum value of the daily maximum 8-hour average after removing outliers were considered to be effective as a robust representative value which reflects high concentration events.

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In order to examine the effect of yellow sand on the metal dissolution from aluminum bronze sheets and super duralumin boards by precipitation, the artificial corrosion atmospheric exposure test was performed. The dissolution inhibition tendency due to the yellow sand atomizing was observed for aluminum and copper from the super duralumin boards and copper from the aluminum bronze sheets. The corrosion current-corrosion potential was measured, and analyzed assuming the yellow sand as a corrosion inhibitor. For the super duralumin, under the yellow sand atomizing, the dissolution was mainly controlled by a inhibition type cathode reaction. The measured result of the accumulative leaching amount of aluminum and copper was explained by this reaction type. For the aluminum bronze, the dissolution was controlled with an inhibition type or a mixed inhibition type anode reaction, which corresponds to the result of the accumulative leaching amount of copper. The yellow sand is assumed to act as a corrosion inhibitor.

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We have analyzed in detail an episode of PM_2.5 from 4 to 7 February 2011 over Japan. The peak time of the PM_2.5 concentration was delayed from west to east along the Sea of Japan on February 4th. High concentrations of PM₁₀ were observed in Korea on February 3rd. A backward trajectory analysis and satellite data showed that the air mass from Mainland China arrived at many sites in Japan. PM_2.5 filter samples were collected at ten sites during the high concentration episode. The chemical composition of PM_2.5 at Miyazaki and Okayama did not change during the episode. On the other hand, the ratio of sulfate, nitrate and ammonium to PM_2.5 had increased in direct proportion to the PM_2.5 concentration during the episode on the east side. The ratio of NO₃^-/SO₄^2- was the lowest for the trans-boundary air pollution. The ratio of NO₃^-/SO₄^2- was higher at the urban site for urban pollution. Based on these results, it was suggested that the high concentrations of PM_2.5 were caused by trans-boundary pollution as well as domestic pollutants in the urban areas.

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After the U.S. EPA issued the revised primary PM_2.5 standard in 2006, the D.C. Circuit remanded the annual standard to the EPA because the EPA failed to adequately explain why the standard provided the requisite protection to exposures of fine particles, including protection for at-risk populations. The EPA then prepared the PM ISA reviewing the new scientific information, and developed the Quantitative Risk Assessment and Policy Assessment. Based on these documents, the EPA issued the Proposed Rule to revise the PM_2.5 standard. After considering the advice of the CASAC and public comments to the Proposed Rule, the EPA decided in the Final Rule to revise the annual PM_2.5 standard by lowering it from 15.0 to 12.0 µg/m³, and to retain the 24-hour PM_2.5 standard at the level of 35 µg/m³. This paper reviews the revision process of the new primary PM_2.5 annual standard.

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