Influences of wind speed and direction on atmospheric particle concentrations and industrially induced noise

In this study, the spatial and temporal relationship of wind speed, atmospheric particles concentration, and the industrial-induced noise levels during different times of the day were examined, using sawmill industrial location around Ile-Ife in Osun of Nigeria as a case study.

Mobile devices were used to measure noise level and basic meteorological parameters were examined and their influences on the noise levels distribution were assessed. The maximum and minimum sound levels; L_max and L_min, the PM₁₀ and PM₁ particle concentrations, wind speeds and directions were measured in the morning (7-9 a.m.), afternoon (12-2) and evening (4-6 p.m.) over 14 consecutive days.

The results revealed that the noise level varies spatiotemporally, much more consistent spatial distribution along the vicinity of sawmill industries. A higher level of noise occurred during the weekday (WD), L_eq > 70 dB(A), compared to weekends (WE). Extreme average noise levels are associated with the immediate neighbourhood of sawmill industrial areas during WD compared to streets and road annexes of the study area. The results also show a very weak relationship between noise and PM₁₀ and PM_coarse for both WD and WE with r < 0.35 for PM₁ and r < 0.20 for PM_coarse. There appears to be a moderate significant correlation between noise level and PM₁ during some meteorological conditions with r > 0.51.

The slight relationship between noise and PM₁ is perhaps a result of wind movement that carries particles from the source region since booth noise and particles mostly originate from the sawmill. The study concludes that wind speeds and directions have a significant influence on both noise level and particle concentration within the study sites.