15 research outputs found
Atmospheric Polychlorinated Naphthalenes in Ghana
A nationwide monitoring of atmospheric POPs (persistent
organic
pollutants) was conducted in Ghana between May and July 2010, applying
polyurethane foam (PUF) disk passive air samplers (PAS). Reported
here are preliminary findings on PCNs, an industrial organic contaminant
currently under review for possible listing under the global chemical
treaty. The present results constitute the first set of nationwide
data on air PCNs from a West African country. Contrary to expectation,
air PCNs levels were quite high in Ghana, at an average of 49 ±
5.4 pg/m<sup>3</sup>. The coastal (southern) zone of Ghana appeared
the most impacted, with crude open burning of waste, industrial emissions,
and the harbor environment identified among possible emission factors.
Tri- and tetra-CNs (the lowly chlorinated homologues) predominated
in the atmosphere, altogether constituting approximately 90% of total
PCN homologues composition. Increased volatilization under tropical
conditions was presumed a key factor that contributed to this high
atmospheric input of lowly chlorinated homologues. We further observed
a significant level of fractionation of PCN homologues across the
breadth of the country. The percentage composition of the lowly chlorinated
homologues increased northwards, probably because of their transportation
in the direction of prevailing winds. From congener profile analysis,
PCN-45/36 is proposed as a possible source marker for emissions preempted
by uncontrolled waste burning activities. Dioxin-like toxicity of
air PCNs in Ghana was estimated to range 0.49–5.6 fg TEQ/m<sup>3</sup>. This study brought to the fore the emerging problems of
nonagricultural organohalogens that covertly might be confronting
the environment in African nations like Ghana
Atmospheric Polychlorinated Naphthalenes in Ghana
A nationwide monitoring of atmospheric POPs (persistent
organic
pollutants) was conducted in Ghana between May and July 2010, applying
polyurethane foam (PUF) disk passive air samplers (PAS). Reported
here are preliminary findings on PCNs, an industrial organic contaminant
currently under review for possible listing under the global chemical
treaty. The present results constitute the first set of nationwide
data on air PCNs from a West African country. Contrary to expectation,
air PCNs levels were quite high in Ghana, at an average of 49 ±
5.4 pg/m<sup>3</sup>. The coastal (southern) zone of Ghana appeared
the most impacted, with crude open burning of waste, industrial emissions,
and the harbor environment identified among possible emission factors.
Tri- and tetra-CNs (the lowly chlorinated homologues) predominated
in the atmosphere, altogether constituting approximately 90% of total
PCN homologues composition. Increased volatilization under tropical
conditions was presumed a key factor that contributed to this high
atmospheric input of lowly chlorinated homologues. We further observed
a significant level of fractionation of PCN homologues across the
breadth of the country. The percentage composition of the lowly chlorinated
homologues increased northwards, probably because of their transportation
in the direction of prevailing winds. From congener profile analysis,
PCN-45/36 is proposed as a possible source marker for emissions preempted
by uncontrolled waste burning activities. Dioxin-like toxicity of
air PCNs in Ghana was estimated to range 0.49–5.6 fg TEQ/m<sup>3</sup>. This study brought to the fore the emerging problems of
nonagricultural organohalogens that covertly might be confronting
the environment in African nations like Ghana
The impact of polybrominated diphenyl ether prohibition:a case study on the atmospheric levels in China, Japan and South Korea
Abstract The atmosphere is an important medium which could directly reflect the changes of pollutant sources. Worldwide, the commercial products of polybrominated diphenyl ethers (PBDEs) have been officially restricted and subsequently prohibited. For the purpose of evaluating their concentration after prohibition, passive air samplers (PASs) were therefore deployed again across the East Asia during two periods in 2008 after the initial deployment 4 years ago. When compared with the data in 2004, the atmospheric concentrations of PBDEs have declined significantly. Spatially, the PBDE level in China was still the highest, with a mean value of 15.4 pg m− 3, and in Japan was the lowest (2.47 ± 1.12 pg m− 3) in the East Asia. Moreover, the relatively high concentrations were observed at sites where there are electronic or e-waste recycling industries, and this is particularly true in China, suggesting that illegally imported e-waste is still a typical source of PBDEs in this region
Passive air sampling of PCBs, organochlorine compounds and PBDEs across Asia.
Asia is of global importance economically, yet data on ambient persistent organic pollutant levels are still sparse for the region, despite international efforts under the Stockholm Convention to identify and reduce emissions. A large-scale passive air sampling survey was therefore conducted in Asia, specifically in China, Japan, South Korea, and Singapore. Polyurethane foam disks were deployed simultaneously at 77 sites, between Sept 21 and Nov 16, 2004, and analyzed for polychlorinated biphenyls (PCBs), organochlorine compounds (hexachlorobenzene (HCB), dichlorodiphenyltrichloroethanes (DDTs), chlordane), and polybrominated diphenyl ethers (PBDEs). The meteorological conditions prevailing in the region at this time facilitated the assessment of local/regional differences in atmospheric emissions, because large-scale advection effects due to monsoons or dust storms did not occur. Air concentrations estimated assuming an average sampler uptake rate of 3.5 m3/day ranged as follows (pg m-3): PCBs, 5−340; HCB, 10−460; DDTs, 0.4−1800; chlordanes, 1−660; PBDEs, <0.13−340. South Korea and Singapore generally had regionally low concentrations. Elevated concentrations of PCBs, DDTs, and HCB occurred at sites in China, higher than reported in a similar recent sampling campaign in Europe. Chlordane was highest in samples from Japan (which also had elevated levels of PCBs and DDTs) and was also elevated in some Chinese locations. PBDE levels were generally low in the region
Seasonal patterns and current sources of DDTs, chlordanes, hexachlorobenzene and endosulfan in the atmosphere of 37 Chinese cities.
China has a history of large scale production and application of organochlorine pesticides (OCPs) although, data on their nationwide distribution and seasonal variations in the atmosphere is still sparse. Passive air samplers (PAS) were therefore utilized to obtain seasonal data from 37 Chinese cities and three background sites in 2005. Concentrations and spatial and seasonal distribution of dichlorodiphenyltrichloroethanes (DDTs), chlordanes (CHLs), hexachlorobenzene (HCB), and endosulfans (Endo) are presented in this paper, and their potential sources are discussed based on the data-set. It is estimated that ca. 95% of DDTs present in the atmosphere of Chinese cities was still from technical DDT, while only ca. 5% was “dicofol-type of DDT”. DDT application for public health control and DDT activated antifouling paint for fishing ships may be the two most important current sources of technical DDT. The DDT concentrations in several Chinese cities seem to match well with the reported DDT concentrations in human breast milk. A low TC/CC ratio was observed across China in the winter to spring, which may provide a fingerprint of Chinese chlordane emission. It was suggested that “weathered” chlordane emitted from urban construction foundations in winter may give the distinctively low TC/CC ratio. The data showed that China is an important global source for HCB. Higher HCB concentrations were observed in winter and spring, and in colder cities, highlighting an important contribution from combustion sources. Samples with higher endosulfan concentrations occurred in the cotton production areas, indicating its major use in killing cotton pests