Impacts of environmental parameters on sick building syndrome prevalence among residents: a walk-through survey in Rasht, Iran

Abstract

Background: This study evaluated the prevalence of sick building syndrome (SBS) in Rasht, Iran, a subtropical climate with wetter cold season city, during the autumn and winter months of 2020, focusing on the effects of noise and ventilation. Methods: A total of 420 residents completed the indoor air climate questionnaire (MM040EA), and a walk-through survey of 45 randomly selected residential units assessed environmental noise, ventilation rate, and luminous conditions. Results: Approximately 38.2% reported SBS symptoms in the past three months. Significant associations were found between SBS and dim light (P-value = 0.012, OR = 2.1, CI = 1.09-4), noise (P-value = 0.031, OR = 1.75, CI = 1.1–2.9), passive smoking (P-value < 0.01, OR = 2.6, CI = 1.22–5.4), static electricity (P-value < 0.01, OR = 3.8, CI = 1.15–12.6), bad air (P-value < 0.01, OR = 4.6, CI = 1.6–13), and high room temperature (P-value = 0.039, OR = 2.6, CI = 1.13–5.95) at α = 0.05. The field survey revealed that 75.5% of units exceeded the national noise threshold of 55 dBA. The average ventilation rate was 20 lit/(p.sec), while 32% of the units reported low or moderate lighting during daytime hours. No significant association was found between the type of interior wall finishing or heating systems and SBS. Stronger correlation was observed between noise and SBS in districts with higher traffic-induced noise. Conclusion: Considering high noise levels in residential areas, local authorities must prioritize noise insulation policies in building design and construction.