Nitrogen can substitute helium as a mobile phase in the analysis of wastewater treatment matrices for persistent organic pollutants by gas chromatography - electron capture detection system.

Municipal wastewater treatment plants are required to monitor persistent organic pollutants (POPs) in their wastewater treatment related discharges and to assess the impact of the discharges on the environment and public health. One tool for monitoring chlorinated organic pollutants particularly is a gas chromatographic (GC) system coupled to a pair of halogen-specific electron capture detectors (ECDs) with helium (He) as the mobile phase. He supplies, however, has become inconsistent and unreliable lately. In its place, N2 gas is evaluated in this study as a potential substitute for He in quantifying organochlorine pesticides, polychlorinated biphenyls, chlordane congeners and toxaphene in wastewater treatment related matrices (influent, effluent, benthic sediment, mussel tissue, and biosolids/sludge). N2 is inert, inexpensive and requires no additional hardware to incorporate into the basic functions of a GC-ECD. Our results show that, with the usual data quality controls (blank, laboratory control, matrix spike/duplicate and proficiency testing samples, and the fact that certified reference materials data met requirements), N2 can replace He for regulatory purposes. And when necessary, the N2-based retention times (tN) can be predicted reliably from He-based retention times (tHe), irrespective of column chemistry or POPs (here: tN = 1.90tHe + 0.04, R2 = 0.996).

Assessing the health risks of consuming 'sachet' alcohol in Acoli, Uganda.

The increased mortality rate among the Acoli people of northern Uganda is anecdotally blamed on excessive consumption of cheap and widely available sachet-packaged alcohol in the region. In this paper, we quantify this perceived association by determining statistically the health risks associated with ingesting 20 heavy metals in 17 popular spirits products consumed in Acoli. Thirteen of these products were industrially packaged in sachets (locally known as 'sachet,' waragi, arege or moo lyec) and four were locally produced Lira-Lira spirits from Bolo, Awere and Teso Bar in the region and Nsambya in southern Uganda. A Scottish whisky purchased in San Diego (USA) was our reference. Risk assessment was performed according to standardized protocols developed by the United States Environmental Protection Agency (US EPA). Our results show that a strong correlation indeed exists between health risks and ingestion of spirits in Acoli. At >2.5 sachets/day for 240 day/year over a lifetime for example, the risk of developing cancer due to exposure to As, Pb and Cr alone is 1 in 102,041. This estimate excludes ethanol, a known carcinogen, and 17 heavy metals also studied due to lack of their cancer slope factors. The primary non-cancer related health risk factor in all samples tested is ethanol with unacceptably high health index of four. The Lira-Lira spirits, with 100-6000% copper above the US EPA limit for intake by oral ingestion in water, would be the 'cleanest' without copper and at par with the Scottish whisky. Collectively, we find that no amount of alcohol consumed in Acoli is safe. Preventive measures are therefore recommended to reduce mortality in Acoli in particular, and in Uganda in general. These measures should include public education, better public policies, creating productive economic activities other than brewing alcohol, and social activities that engage people away from drinking.