Browsing by Author "Kobara, Y."

Now showing 1 - 3 of 3

Atmospheric burden of organochlorine pesticides in Ghana
(Chemosphere, 2014-05) Hogarh, J.N.; Seike, N.; Kobara, Y.; Ofosu-Budu, G.K.; Carboo, D.; Masunaga, S.
Organochlorine pesticides (OCPs) are subject to the Stockholm Convention on POPs and have been banned or restricted globally. In Ghana, concerns of illicit applications of some OCPs have been raised in recent times. Applying polyurethane foam (PUF) disk passive air samplers (PAS), the levels of OCPs in the atmosphere and their spatial resolution were investigated. It was the first nationwide coverage of OCPs monitoring in Ghana. ∑DDTs and endusulfans constituted the highest burden of atmospheric OCPs in Ghana, at average concentrations of 156±36 and 153±28pgm-3, respectively. Mirex had the lowest concentration (0.2±0.01pgm-3). From the chemical signatures of the various OCPs, we deduced that DDT, endosulfans and heptachlor were freshly applied at certain sites, which were all agricultural sites. The OCPs were spatially resolved as a function of the types of crops cultivated in different areas, legacy issues and recent applications. © 2013 Elsevier Ltd.
Atmospheric monitoring of organochlorine pesticides across some West African countries
(Environmental Science and Pollution Research, 2018-11) Isogai, N.; Hogarh, J.N.; Seike, N.; Kobara, Y.; Oyediran, F.; Wirmvem, M.J.; Ayonghe, S.N.; Fobil, J.; Masunaga, S.
Most African countries have ratified the Stockholm Convention on persistent organic pollutants (POPs) and are expected to reduce emissions of POPs such as organochlorine pesticides (OCPs) to the atmosphere. Emerging evidence, however, suggests that there are contemporary sources of OCPs in African countries despite the global ban on these products. This study investigated the atmospheric contamination from OCPs in four West African countries—Togo, Benin, Nigeria, and Cameroon—to ascertain the emission levels of OCPs and the characteristic signatures of contamination. Polyurethane foam (PUF) disk passive air samplers (PAS) were deployed in each country for ca. 55 days in 2012 and analyzed for 25 OCPs. Hexachlorocyclohexanes (HCHs) and DDTs constituted the highest burden of atmospheric OCPs in the target countries, at average concentrations of 441 pg m−3 (range 23–2718) and 403 pg m−3 (range 91–1880), respectively. Mirex had the lowest concentration, ranged between 0.1 and 3.3 pg m−3. The concentration of OCPs in rainy season was higher than in dry season in Cameroon, and presupposed inputs from agriculture during the rainy season. The concentrations of ∑25 OCPs in each country were in the following order: Cameroon > Nigeria > Benin > Togo. There was significant evidence, based on chemical signatures of the contamination that DDT, aldrin, chlordane, and endosulfan were recently applied at certain sites in the respective countries. © 2016, Springer-Verlag Berlin Heidelberg.
Source characterization and risk of exposure to atmospheric polychlorinated biphenyls (PCBs) in Ghana
(Springer Verlag, 2018-06) Hogarh, J.N.; Seike, N.; Kobara, Y.; Carboo, D.; Fobil, J.N.; Masunaga, S.
With recent evidence that persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs) are emerging in environmental media in some developing countries that otherwise have sparing production and usage history, it has become important to identify such contemporary source factors of PCBs and the risks this may pose, in line with the global consensus on POP management and elimination. The present study investigated contaminations from atmospheric PCBs in Ghana, deciphered source factors, and accessed risk of exposure to dioxin-like PCBs (DL-PCBs). Atmospheric PCBs were monitored by deployment of PUF-disk passive air samplers (PAS) at several sites across Ghana for 56 days. Atmospheric ∑190PCB concentration in Ghana ranged from 0.28 ng/m3 in Kumasi to 4.64 ng/m3 at Agbogbloshie, a suburb in Accra noted for informal electronic waste (e-waste) recycling activities. As high as 11.10 ng/m3 of PCB concentration was measured in plumes from uncontrolled open burning of e-wastes at Agbogbloshie. Applying statistical source characterization tools, it emerged that e-wastes were a major contributor to the environmental burden of atmospheric PCBs in Ghana. The risk of DL-PCB toxicity via inhalation in the Agbogbloshie area was 4.2 pg TEQ/day, within similar order of magnitude of an estimated risk of 3.85 pg TEQ/day faced by e-waste workers working averagely for 8 h per day. It is suggested that elimination of e-waste sites would help to significantly reduce PCB-related toxicity issues in Ghana. [Figure not available: see fulltext.]. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature