While effective analytical techniques to promote the long-term intensive monitoring campaign of particulate heavy metals have been well established, efforts to interpret these toxic chemical contents into policy are lagging behind. In order to ameliorate the interpretation of evidence into policies, environmental scientists and public health practitioners need innovative methods to emphasize messages concerning adverse health effects to state and local policymakers. In this study, three different types of health risk assessment models categorized by exposure pathways. Namely, ingestion, dermal contact, and inhalation were quantitatively evaluated using intensive monitoring data of 51 PM-bound metals that were collected on three consecutive days, from 17 November 2010 to 30 April 2011 in the heart of Bangkok. Although different exposure pathways possess different magnitudes of risk for each PM-bound metal, it can be concluded that ingestion of dust causes more extensive risk to residents compared with inhalation and dermal contact. The investigation of enrichment factors reveals the overwhelming influences of vehicular exhausts on 44 selected metal concentrations in Bangkok. These findings are in agreement with previous studies that highlight the role of public transportation and urban planning in air pollution control.

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The mean maximum urban heat island (UHI) intensity in three major cities in Thailand was investigated by using data measured at two meteorological observatories (an urban site and rural site) in each study area for the period 2004 to 2008. Thermal contrasts between the urban and rural sites were positive which indicated that most of the time the air temperatures at the urban sites were higher than the air temperatures at the rural sites. The strongest mean maximum UHI intensity occurred in the nighttime and in the early morning, while the weakest mean maximum UHI intensity was reached during the daytime. The results indicated that UHI events occurred more frequently in the nighttime than in the daytime. Seasonal analyses showed the mean maximum UHI intensity was weakest in the rainy season (May-October) and was strongest in the dry season (November-April).

This paper studies the relevance between carbon dioxide (CO₂) absorption rates of common trees in Chulalongkorn University (Thailand), and environmental factors -- light intensity, air temperature, leaf temperature, and CO₂ concentration in air -- by forming non-linear models. The common tree species are Pterocarpus indicus, Samanea saman, Peltophorum pterocarpum, and Terminalia catappa. Measuring CO₂ absorption was done by chamber analysis approach. The experiment was carried out by gauging 10 leaves, 7 hours per day, and 2 days per species. According to the models, it is obvious that light intensity is the most influential factor to CO₂ absorption for all studied species. Peltophorum pterocarpum and Samanea saman reach their maximum CO₂ uptake rates of 24.5 and 20.9 CO₂ µmol m^-2s^-1, when photosynthetically active radiation is 1100 and 1500 µmol m^-2s^-1 respectively. The other two do not reach their maximum rate within model data range. The regressions were best fitted with Gaussian function and Sigmoidal function. It is also suggested that Peltophorum pterocarpum and Samanea saman are good carbon sink and they should be planted more in the city for optimal CO₂ absorption.