Health Risk Assessment of Residents in a Tourist City: A Case Study of Nakhon Si Thammarat Province

Abstract

Nakhon Si Thammarat is one of the most popular tourist destinations among the secondary tourism cities according to economic promotions. The rapid growth of the tourism industry is evidenced by increasing road traffic, especially at weekends, contributing to high nitrogen dioxide (NO2) concentration. The concentration of NO2 was measured in the main tourist destinations of Nakhon Si Thammarat Province. Likewise, health risks from NO2 exposure were also evaluated for the local residents. Air mass movement was applied to indicate risk areas of non-cancer health effects from exposure to NO2. Air samples were collected over 24 hours using a passive sampling technique at 3 areas in the tourist destination on weekdays and weekends during the wet season in 2018 and 2019. Results showed that NO2 concentrations at weekends were 2 - 3 times higher than on weekdays due to increased vehicular traffic. Anthropogenic activities had a greater influence than meteorological conditions on pollutant concentration. The NO2 concentration was within the ambient air quality standard, but toxicological risk quotients for the residents were above the recommended limits for human health. Findings indicated that local residents risked non-cancer health effects from long-term exposure to NO2. Therefore, sensitive residents should avoid outdoor activities on weekends. Moreover, the tourism authority should consider controlling visitor numbers, providing a parking area, and providing public transportation systems to reduce traffic-related pollutants for sustainable tourism in Thailand.