Sound Over Troubled Waters: Noise Pollution in Prek Toal, Cambodia

Amy Whetter


Environmental noise pollution, or excessive noise related to machinery operation and vehicular transportation, is a common problem in urban environments. Less understood is the effect that chronic environmental noise can have in rural environments, where there is greater potential for disruption of native ecosystems and the quality of life in small villages. Chronic exposure to noises above 85 decibels causes noise induced hearing loss (NIHL) in humans, which has irreversible effects. Even less understood is the effect that chronic noise can have on animals that thrive in less urbanized environments. Here, I examine the effect of noise pollution caused by motor boats in the floating village of Prek Toal, Cambodia. I identify the types of motorboats used along the Sangker river, the river that runs through the village, and experimentally measure their maximum sound intensities across a various distances from 0-100m from the motor. The effect of the noise on the boat is examined to address the occupational hazard to the driver. The observational data is also used to derive an empirical equation for sound decay that is specific to this rural environment. This equation is used to map the spatial distribution of environmental noise pollution within the village and identify zones of noise induced hearing loss along the Sangker river. A total of sixty villagers were surveyed to identify the types of motors present in Prek Toal. The two major motor companies, Yokohama and Hinota, offer motors with a wide range of horsepower. Sound intensity measurements revealed the mean range of sound that drivers are exposed to is 93 dB(A) to 112 dB(A), with the majority of motors above 100 dB(A)s. This exceeds the minimum for NIHL, demonstrating that drivers in Prek Toal are exposed to hearing-related occupational hazards while driving. The empirically derived sound decay equation reveals an exponential relationship between sound and distance in Prek Toal. This relationship matches what has been found in other studies. A spatial analysis of the observational data reveal that each boat has a minimum NIHL radius of 45 meters.