Atmospheric Concentrations of Polycyclic Aromatic Hydrocarbons in the Watershed of Lake Victoria, East Africa

Abstract

In the first study of its kind in Africa, PAHs were measured in high volume (24 h) air samples collected from two sampling stations, at Kakira and Entebbe (KAK and EBB, respectively) within the Lake Victoria watershed in Uganda, to assess source contributions and generate a baseline reference data set for future studies in the East African region. Sampling was conducted over two periods [2000-2004 (KAK and EBB1) and 2008-2010 (EBB2)]. The samples were extracted by accelerated solvent extraction and analyzed for 30 PAHs by GC-MS. The mean total PAH concentrations (ng/m(3)) were found to be 74.3 (range; 19.3-311, N = 39) for KAK, 56.8 (range; 13.3-126, N = 22) for EBB1 and 33.1 (range; 4.91-108, N = 56) for EBB2. The 3-ringed PAHs were the most predominant group with mean concentrations of 35.9 ng/m(3)(EBB1), 30.5 ng/m(3)(KAK) and 23.2 ng/m(3)(EBB2). Naphthalene had an exceptionally high mean concentration (21.9 ng/m(3)) for KAK compared to 0.44 and 0.39 ng/m(3) in EBB1 and EBB2 respectively, likely due to intensive agricultural operations nearby KAK. Principal component and diagnostic ratio analyses showed that the measured levels of PAHs were associated with mixed sources, combustion of petroleum, and biomass being the major sources.

Chemical and Biological Components of Urban Aerosols in Africa: Current Status and Knowledge Gaps

“…Map of Africa showing countries where studies on polycyclic aromatic hydrocarbons (PAHs) and their nitro-derivatives (NPAHs) in ambient air were conducted. The sampling duration, concentration of PAHs and NPAHs, and number of analyzed PAHs and NPAHs species; shaded black color indicates PAHs and NPAHs studies carried in Algeria [117], Egypt [116], and Rwanda [34] and shaded gray color indicates PAHs studies carried in Kenya [118], Mali [120], Sierra Leonne [121], Senegal [120], South Africa [119], and Uganda [122]. …”

Characterization and Risk Assessment of Atmospheric PM2.5 and PM10 Particulate-Bound PAHs and NPAHs in Rwanda, Central-East Africa

“…High concentrations of dominant PAH compounds in this study were fluoranthene (Flu), BaP, benzo(b)fluoranthene (BbF), and benz(g,h,i)perylene (BPe) (Figure S5 of the SI), which have been previously observed in East African and East Asian countries influenced by biomass burning and vehicle emission. 18,33 BaP is classified as ga roup 1 carcinogenic to humans. 34 In this study, the mean concentrations of BaP detected in PM 2.5 and in PM 10 at the urban roadside area, urban background, and rural area (Table 1 and Table S9 of the SI) were higher than that recommended by WHO guidelines (1 ng/m 3 ).…”

Exposure and Public Health Effects of Polycyclic Aromatic Hydrocarbon Compounds in Sub-Saharan Africa: A Systematic Review

“…Naphthalene was found to have an exceptionally high mean concentration of 21.9 ng/m 3 . 44…”

“…Naphthalene was found to have an exceptionally high mean concentration of 21.9 ng/m 3 . 44 The PAHs contamination within their study area was related with agricultural activities, petroleum combustion, and the use of biomass fuels.…”