Volatile Organic Compound Composition of Urban Air in Nairobi, Kenya and Lagos, Nigeria

Abstract

Sub-Saharan Africa is seeing rapid urbanization, with the population of cities such as Lagos and Nairobi growing at a rate of 3–4% a year. The region is extremely under-sampled for all air pollutants, particularly VOCs, which are useful markers for source apportionment as well as toxic in their own right. There are many contributors to air pollution in the region, and studies examining fine particulate pollution implicate traffic as the primary source in urban areas. In this pilot study, VOCs were analysed at a selection of roadside and urban background locations in Nairobi and Lagos, and 74 VOCs were quantified. GC×GC–MS/FID analysis revealed all locations were dominated by hydrocarbons typical of vehicle emissions, with the aromatic hydrocarbons benzene and toluene among the most abundant VOCs. Typical personal exposure scenarios for citizens of the cities were calculated to far exceed those of a resident in a city in Europe/US. Finally, the calculated ozone forming potential of the VOCs measured was found to be similarly high to other large cities studied with similar air pollution problems. Further study is therefore essential to determine the full extent of VOC pollution in the region and its impact on tropospheric chemistry.

Residential VOCs concentration levels in Nsukka, Nigeria

“…Comparing urban and rural households shows that the metropolitan median TVOCs concentration levels are 1.7 and 2 times more than the rural outdoor levels during the dry and wet season, respectively. In Lagos, Nigeria, the TVOC in the metropolitan area is 3 times larger than the urban background levels (Cordell et al, 2021). Our result aligns with the literature (Roba et al, 2014;Strosnider et al, 2017).…”

Indoor Air Quality Assessment Using a Low-Cost Sensor: A Case Study in Ikere-Ekiti, Nigeria

“…Although earlier IAQ studies [2][3][4] have provided insightful information, they frequently concentrate on certain pollutants or make use of expensive monitoring tools, which limits the breadth and depth of data collection. On the other hand, our study covers a wide range of CO 2 , NO 2 , O 3 , and different PM fractions in addition to single pollutants.…”