Short-term effects of the chemical components of fine particulate matter on pulmonary function: A repeated panel study among adolescents.

The effects of the chemical components of fine particulate matter (PM2.5) have been drawing attention. However, information regarding the impact of low PM2.5 concentrations is limited. Hence, we aimed to investigate the short-term effects of the chemical components of PM2.5 on pulmonary function and their seasonal differences in healthy adolescents living on an isolated island without major artificial sources of air pollution. A panel study was repeatedly conducted twice a year for one month every spring and fall from October 2014 to November 2016 on an isolated island in the Seto Inland Sea, which has no major artificial sources of air pollution. Daily measurements of peak expiratory flow (PEF) and forced expiratory volume in 1 s (FEV1) were performed in 47 healthy college students, and the concentrations of 35 chemical components of PM2.5 were analyzed every 24 h. Using a mixed-effects model, the relationship between pulmonary function values and concentrations of PM2.5 components was analyzed. Significant associations were observed between several PM2.5 components and decreased pulmonary function. Among the ionic components, sulfate was strongly related to decreases in PEF and FEV1 (-4.20 L/min [95 % confidence interval (CI): -6.40 to -2.00] and - 0.04 L [95 % CI: -0.05 to -0.02] per interquartile range increase, respectively). Among the elemental components, potassium induced the greatest reduction in PEF and FEV1. Therefore, PEF and FEV1 were significantly reduced as the concentrations of several PM2.5 components increased during fall, with minimal changes observed during spring. Several chemical components of PM2.5 were significantly associated with decreased pulmonary function among healthy adolescents. The concentrations of PM2.5 chemical components differed by season, suggesting the occurrence of distinct effects on the respiratory system depending on the type of component.

Influence of marine vessel emissions on the atmospheric PM2.5 in Japan's around the congested sea areas.

In recent years, PM2.5 concentrations in Japan have decreased as China's measures against the emission of air pollutants were strengthened and the subsequent transport of air pollutants to Japan decreased. On the other hand, along the coast of the Seto inland sea in Japan, the PM2.5 concentration remains high. In this study, in order to evaluate the impact of air pollutants from marine vessels on PM2.5 along the coast of the Seto inland sea, PM2.5 was seasonally collected in the vicinity of a congested sea lane (Akashi Strait) in 2016 and 2017, and a receptor-source analysis was performed to determine the main components of the collected PM2.5. In Japan's congested sea lane, the vanadium (V) concentration was very high and showed a strong correlation with the nickel (Ni) concentration. Also, the V/Ni ratio rose when the wind blew from the sea lane. Positive Matrix Factorization (PMF) analysis clarified that the contributions from marine vessel emissions to PM2.5 at the current observation sites were 2.5-2.7 µg m-3 (17.3-21.4%), and the marine vessel emissions were the main source of PM2.5 along the coast of the Seto inland sea. Fuel oil regulations for marine vessels to be introduced in January 2020 are expected to improve the air quality of coastal areas.

The Characteristics of Polycyclic Aromatic Hydrocarbons in Different Emission Source Areas in Shenyang, China.

Particulate matter (PM) was collected in three different areas, SY-1, SY-2, and SY-3, in Shenyang, China, during the warm and cold seasons from 2012 to 2014. SY-1 was located beside a thermal power plant, far from the central area. SY-2 was near a coal heating boiler on the main road, close to the central area. SY-3 was on the main road, without fixed emission sources. Nine PM-bound polycyclic aromatic hydrocarbons (PAHs) were analyzed. The results showed that the mean concentration of total PAHs was higher in the cold season (92.6-316 ng m-3) than in the warm season (18.4-32.2 ng m-3). Five- and six-ring PAHs occupied a large percentage at all sites in the warm season, and four-ring PAHs were the dominant components in the cold season. Several diagnostic PAH ratios indicated that the main sources of PAHs in Shenyang in the warm and cold seasons were not only coal burning but also vehicle emission. In this study, we suggest that a benzo[a]pyrene/benzo[ghi]perylene ratio ([BaP]/[BgPe]) of 0.6 was a useful indicator to speculate the relative significance of coal burning and vehicle exhaust. Although the Shenyang government has undertaken actions to address air pollution, the PM and PAH concentrations did not decrease significantly compared to those in our previous studies. The cancer risk calculated from the BaP equivalent total concentration at all three sites in the warm and cold seasons exceeded the acceptable limit established by the US EPA.

Stronger association between particulate air pollution and pulmonary function among healthy students in fall than in spring.

Previous studies have reported the short-term effects of particulate air pollution on health. However, most of those studies were relatively short in duration, with only a few, in healthy adolescents. We investigated the short-term effects of particulate air pollution on pulmonary function in healthy adolescents over a long period. A panel study was repeatedly conducted twice a year for about one month each, in spring and fall from 2014 to 2016, in an isolated island in the Seto Inland Sea, Japan. Daily measurements of peak expiratory flow (PEF) and forced expiratory volume in 1 s (FEV1) were performed in a total of 48 healthy college students aged 15-19 years. The ambient concentrations of particulate matter with diameter ≤2.5 µm (PM2.5) and between 2.5 and 10 µm (PM10-2.5), and black carbon (BC) were continuously measured. A mixed-effects model was used to investigate the relationships between air pollutants and pulmonary function. In the overall analyses of the six study periods, decreases in the PEF and FEV1 were significantly associated with increases in the PM2.5 and BC concentrations. The greatest decrease was found in FEV1 (-1.97% [95% confidence interval (CI): -2.90, -1.04]), which was associated with an interquartile range (IQR) increase in the 0-72-h average concentrations of PM2.5 (14.1 µg/m3). Neither PEF nor FEV1 were associated with PM10-2.5 concentrations. In the analyses by season, both the PEF and FEV1 values decreased significantly in relation to increases in the PM2.5, PM10-2.5 and BC concentrations in the fall. However, in spring, both PEF and FEV1 showed weak associations with each of the pollutants. In conclusion, relatively low increases in the ambient particulate matter levels were associated with reduced pulmonary function among healthy adolescents. This association was stronger in fall than in spring.

Acute effects of air pollutants on pulmonary function among students: a panel study in an isolated island.

BACKGROUND: Many epidemiological studies on the health effects of air pollutants have been carried out in regions with major sources such as factories and automobiles. However, the health effects of air pollutants in regions without major sources remain unclear. This study investigated the acute effects of ambient air pollution on pulmonary function among healthy students in an isolated island without major artificial sources of air pollutants. METHODS: A panel study was conducted of 43 healthy subjects who attended a school in an isolated island in the Seto Inland Sea, Japan. We measured the forced expiratory volume in 1 s (FEV1) and peak expiratory flow (PEF) every morning for about 1 month in May 2014. Ambient concentrations of particulate matter ≤ 2.5 µm in diameter (PM2.5), particulate matter between 2.5 and 10 µm in diameter (PM10-2.5), black carbon (BC), ozone (O3), and nitrogen dioxide (NO2) were measured. The associations between the concentrations of air pollutants and pulmonary function were analyzed using mixed-effects models. RESULTS: A decrease in FEV1 was significantly associated with BC concentrations (-27.28 mL [95%confidence interval (CI):-54.10,-0.46] for an interquartile range (IQR) increase of 0.23 µg/m3). The decrease in PEF was significantly associated with indoor O3 concentrations (-8.03 L/min [95% CI:-13.02,-3.03] for an IQR increase of 11 ppb). Among subjects with a history of allergy, an increase in PM2.5 concentrations was significantly associated with low FEV1. In subjects with a history of asthma, an inverse association between the indoor O3 concentration and pulmonary function was observed. CONCLUSIONS: Our results demonstrate that increases in BC and O3 concentrations have acute effects on the pulmonary function among students in an isolated island without major artificial sources of air pollutants.

Change of atmospheric condition in an urbanized area of Japan from the viewpoint of rainfall intensity.

The atmospheric condition in an urbanized area of Japan was examined from the viewpoint of a 14-year trend in the rainfall intensity. To cancel the wide-area meteorological phenomena such as a typhoon and a front, the rainfall datasets obtained not only in an urban area but also in a rural area was studied. The rainfall datasets collected on a 0.5 mm rainfall basis was used. The rainfall intensity dominantly increased in urban area, while that in rural area neither increased nor decreased. An increasing trend was clearly observed for rainfall with precipitation amounts of 5 and 10 mm. Rainfall with precipitation amounts of 15 and 20 mm showed neither an increasing nor a decreasing trend. The results of this study show that there is a high probability of a connection between the urbanization and the change of rainfall intensity.

Grouping and representativeness of monitoring stations based on wind speed and wind direction data in urban areas of Japan.

Data on wind speed and wind direction from 27 air pollution monitoring stations in an urban area of Japan were analyzed and studied for the future assessment of the urban heat island phenomenon. A cluster analysis clarified the regionality of the wind speed and wind direction. In the study area, land and sea breeze developed and controlled the wind direction. On the other hand, the mountain and valley wind should be studied to determine their typical behavior.

Characteristic air temperature distributions observed in summer and winter in urban area in Japan.

The air temperature distributions in August (summer) and December (winter) were measured in an approximately 15 x 15-km urban area in Hyogo Prefecture, Japan, in order to study the spatial distribution of the air temperature and to propose effective measures against the heat island phenomenon. The air temperature was measured mainly by using thermometer shelters installed in an elementary school and a junior high school. The characteristic air temperature distribution depended on the season. The air temperature was higher inland than in the coastal region in August but was higher in the coastal region in December. The air temperature index indicated that the area where higher air temperatures would most likely appear was 5 to 10 km inland from the coast in August and around the coast in December. The seasonal air temperature distribution was presumably due to the strength of solar radiation and anthropogenic exhaust heat.

Field survey of trans-boundary air pollution with high time resolution at coastal sites on the Sea of Japan during winter in Japan.

An intensive field survey, with 6-h measurement intervals, of concentrations of chemical species in particulate matter and gaseous compounds was carried out at coastal sites on the Sea of Japan during winter. The concentration variation of SO(2)(g) and HNO(3)(g) were well correlated, whereas the NH(3)(g) concentration variation had no correlation with those of SO(2)(g) and HNO(3)(g). The NH(4) (+) (p)/non-sea-salt- (nss-)SO(4) (2 -)(p) ratio in particulate matter was mainly affected by the location of the sampling site. One or more concentration peaks of nss-Ca(2 +) for survey period were observed. Backward trajectories analyses for the highest nss-Ca(2 +) concentration peaks showed some inconsistency in pathways. We consider that insufficient mixing of the atmosphere and/or insufficient time for the transported air pollutants to react with those discharged locally are the most likely explanations for the discrepancies between the measured products [HNO(3)][NH(3)] and the calculated values.

Comparative field study on precipitation, throughfall, stemflow, fog water, and atmospheric aerosol and gases at urban and rural sites in Japan.

Precipitation collected by a wet-only sampler (WP), precipitation collected by a filtering-type bulk sampler (BP), throughfall (TF), stemflow (SF), fog water (FW), and atmospheric aerosol and gases were collected at two sites with different site classifications: an urban site (Mt. Rokko) and a rural site (Mt. Awaga) to investigate canopy-atmosphere interactions and to study the chemistry of precipitation in forested areas located in different atmospheric conditions. Compared to those at the rural site, the monthly volume-weighted pH values at the urban site were not significantly (p>0.05) different for WP, higher (p<0.05) for BP, not significantly (p> 0.05) different for TF, lower (p<0.01) for SF, and lower (p<0.01) for FW. The order of mean pH values at the urban site was FW