Efficient collection of viable virus aerosol through laminar-flow, water-based condensational particle growth.

AIMS: State-of-the-art bioaerosol samplers have poor collection efficiencies for ultrafine virus aerosols. This work evaluated the performance of a novel growth tube collector (GTC), which utilizes laminar-flow water-based condensation to facilitate particle growth, for the collection of airborne MS2 viruses. METHODS AND RESULTS: Fine aerosols (<500 nm) containing MS2 coliphage were generated from a Collison nebulizer, conditioned by a dilution dryer and collected by a GTC and a BioSampler. The GTC effectively condensed water vapour onto the virus particles, creating droplets 2-5 µm in diameter, which facilitated collection. Comparison of particle counts upstream and downstream revealed that the GTC collected >93% of the inlet virus particles, whereas the BioSampler's efficiency was about 10%. Viable counts of the GTC-collected viruses were also one order of magnitude higher than those of the BioSampler (P = 0·003). CONCLUSION: The efficiency of the GTC for the viable collection of MS2 viruses exceeds that of industry standard instrument, the BioSampler, by a factor of 10-100. SIGNIFICANCE AND IMPACT OF THE STUDY: This study reveals that the GTC is an effective collector of viable MS2 aerosols, and concludes the instrument will be an effective tool for studying viable virus aerosols and the inhalation risks posed by airborne viruses.

Residential biofuels in South Asia: carbonaceous aerosol emissions and climate impacts.

High concentrations of pollution particles, including "soot" or black carbon, exist over the Indian Ocean, but their sources and geographical origins are not well understood. We measured emissions from the combustion of biofuels, used widely in south Asia for cooking, and found that large amounts of carbonaceous aerosols are emitted per kilogram of fuel burnt. We calculate that biofuel combustion is the largest source of black carbon emissions in India, and we suggest that its control is central to climate change mitigation in the south Asian region.

Optimization of the separation selectivity of PCBs in a hydroorganic reverse-phase liquid chromatography in the presence of cetyltrimethylammonium bromide with fluorescence detection.

The retention of different PCBs of toxicological and environmental interest was studied in a hydro-alcoholic reverse-phase liquid chromatography in the presence of cetyltrimethylammonium bromide (CTAB). The influence of variables like type and percentage of alcohol, concentration of CTAB, temperature and mobile phase flow was determined. According to the aforementioned studies, the appropriate conditions for separation of PCBs in presence of CTAB in a hydro-alcoholic medium are: percentage of 1-Propanol 55% (v/v), concentration of CTAB 5.0 x 10(-3) M, temperature 50 +/- 1 degrees C and mobile phase flow 1 ml min-1.