Human Exposure to Particulate Matter Potentially Contaminated with Sin Nombre Virus

Abstract

The most common mechanism for human exposure to hantaviruses throughout North America is inhalation of virally contaminated particulates. However, risk factors associated with exposure to particulates potentially contaminated with hantaviruses are generally not well understood. In North America, Sin Nombre virus (SNV) is the most common hantavirus that infects humans, causing hantavirus pulmonary syndrome, which has a significant mortality rate (approximately 35%). We investigated human exposure to particulate matter and evaluated the effects of season, location (sylvan and peridomestic environment), and activity (walking and sweeping) on generation of particulates at the breathing zone (1.5 m above the ground). We found greater volumes of small inhalable particulates during the spring and summer compared to the fall and winter seasons and greater volumes of small inhalable particulates produced in peridomestic, compared to sylvan, environments. Also, greater volumes of particulates were generated at the breathing zone while walking compared to sweeping. Results suggest that more aerosolized particles were generated during the spring and summer months. Our findings suggest that simply moving around in buildings is a significant source of human exposure to particulates, potentially contaminated with SNV, during spring and summer seasons. These findings could be advanced by investigation of what particle sizes SNV is most likely to attach to, and where in the respiratory tract humans become infected.

Personal exposure to fine particulate matter concentrations in central business district of a tropical coastal city

“…Both GPS and instrument time were synchronized before every monitoring campaign. The instrument was carried in a backpack, and sampling port was positioned at breathing level (approximately 1.5 m from the ground level) as reported in previous studies (Kaur, Nieuwenhuijsen, and Colvile 2005;Richardson et al 2013;Sloan et al 2016). The monitoring by walking was carried out for about 50 min in each of these areas during three different time periods, i.e., morning (8 a.m.-9 a.m.), afternoon (12.30 p.m.-1.30 p.m.), and evening (4 p.m.-5 p.m.), to get the exposure concentrations at peak time periods.…”

Toward a Mechanistic Understanding of Environmentally Forced Zoonotic Disease Emergence: Sin Nombre Hantavirus

“…(e) What quantities of aerosolized particulate matter are generated by various anthropogenic activities (e.g., Richardson et al. 2013 )? (f) What are the inhalation rates of particulate matter by humans during activities within these buildings?…”

Hantavirus pulmonary syndrome in Canada: An overview of clinical and diagnostic features, epidemiology and prevention

“…Cases of hantavirus pulmonary syndrome have been reported in every month of the year but most occur in the spring and early summer. Seasonal specific-risk factors related to cleaning of structures (e.g., cottage-or farm-associated machinery or buildings) and the increased potential contact with deer mouse excreta at this time of year likely contributes to the seasonality of hantavirus pulmonary syndrome cases (3,6,32).…”