Assessment of Indoor Air Pollution from Burning Local Incense in Ubari, Libya: Concentrations of PM₂.₅ and PM₁₀

Abstract

Burning incense is a prevalent cultural practice in many Arab and Asian countries; however, it significantly contributes to indoor air pollution due to the release of both fine and coarse particulate matter (PM₂.₅ and PM₁₀). This study aimed to evaluate the concentration levels of suspended particulate matter resulting from the combustion of various locally used incense types in Ubari, Libya. Eight commonly used incense samples were analyzed, including oud, shiḥ, fisoʾkh, jarareem, children's incense, oud mixture, jawi, and washaq, utilizing olive wood charcoal as the combustion source. Measurements were taken in a sealed indoor room at intervals of 10, 30, and 60 minutes after ignition, using a Handheld Air Tester (APEX CJ651). Results indicated that background concentrations of PM₂.₅ and PM₁₀ prior to burning were within the World Health Organization's limits (below 25 and 50 µg/m³, respectively). However, the combustion of incense and charcoal led to a significant increase in particle concentrations. The highest emissions were recorded for shiḥ, fisoʾkh, jarareem, and washaq, reaching 500 µg/m³ for PM₂.₅ and 1000 µg/m³ for PM₁₀. In contrast, oud and the oud mixture resulted in the lowest emissions. These findings suggest that certain types of incense may pose health risks by elevating indoor particulate levels well above recommended thresholds. It is advisable to promote the use of low-emission incense and enhance indoor ventilation during burning to reduce exposure.