Concentrations of Particulate Matters during Semester and Semester Break at Nakhon Si Thammarat Municipality, Southern Thailand

Abstract

Traffic related particulate matter (PM) is one of key air pollution problems in big cities in the developing world. Exposure to high levels of PM poses adverse health impacts on humans. Nakhon Si Thammarat is a province in the south of Thailand that is potentially challenging on the increasing levels of PM, particularly at main road intersection. Lak Muang Connection has been identified as one of the particular site having high PM₁₀ due to traffic volume. The objective of this paper was to assess the levels of PM₁₀ concentrations at two schools: primary and high schools located nearby Lak Muang Connection. Sampling periods were divided into two periods: during semester and semester break for each 7 consecutive days. Results revealed that 24-hour average PM₁₀ concentrations were 47 µg/m³ and 52 µg/m³ at the primary and high schools, respectively during semester break while that during semester the PM₁₀ concentrations were 74 µg/m³ and 70 µg/m³, respectively. We found that the differences of average PM₁₀ compared between semester and semester break were approximately 27 µg/m³ and 18 µg/m³, respectively at the primary and high schools. Increasing PM levels could be explained by increasing traffic volume during dropping off/picking up the school children at rush hour periods. With this average increasing PM₁₀, school children may face excess risk of mortality. Appropriate measures for traffic management during the semester could be implemented to cut off the PM levels. Future study should include long-term PM data collection and mathematic models to assess different scenarios of traffic management on PM reduction.