No abstract

No abstract

The objective of this study was to obtain diurnal variation profiles of odor and gas (ammonia [NH3], hydrogen sulfide [H2S], carbon dioxide [CO2]) concentrations and emission rate (OGCER) from confined swine grower/ finisher rooms under three typical weather conditions (warm, mild, and cold weather) in a year. Two grower/ finisher rooms, one with a fully slatted floor and the other with partially slatted floors, were measured for 2 consecutive days under each weather condition. The results revealed that the diurnal OGCER in the room with a fully slatted floor was 9.2-39.4% higher than that with a partially slatted floor; however, no significant differences in the diurnal OGCER were found between these two rooms, except for the NH3 concentrations in August, the NH3 and H2S concentrations and emissions in October, and odor concentrations and emissions in February (p > 0.05). The OGCER variations presented different diurnal patterns as affected by time of day, season, type of floor, ventilation rate, animal growth cycles, in-house manure storage, and weather conditions. Significant diurnal fluctuations in the OGCER (except for the odor concentrations and H2S emissions) were observed in August (p < 0.05); all of the gas emissions in October and the CO2 concentrations and emissions in February also showed significant diurnal variations (p < 0.05). These significant diurnal variations indicated that the OGCER during different periods of a day should be monitored when quantifying OGCER concentrations and emissions; for example, source emission data used in air dispersion modeling to decrease the great incertitude of setback determination using randomly measured data.

No abstract

No abstract

Seasonal odor and gas (ammonia [NH 3 ], hydrogen sulfide [H 2 S], and carbon dioxide [CO 2 ]) concentrations and emission rates (OGCERs) from swine facilities are vital for providing accurate source emissions and reducing the uncertainty of setback distances on the basis of emission data. In this study, a repeated measurement experimental method and a split-block statistical model were used to obtain seasonal OGCER profiles from two types of swine grower-finisher rooms in Saskatchewan, Canada, over a 12-month period. The results indicate that the OGCERs were significantly affected by the sampling month and ambient temperature (P Ͻ 0.05), which indicates that monthly OGCERs should be measured and used as representative monthly or seasonal values in air dispersion models to reduce uncertainties in setback calculations. It was also found that the seasonal OGCERs from the rooms with fully slatted floors were 6.3-40.6% higher than those with partially slatted floors. The seasonal OGCERs (except for the NH 3 concentrations in October, November, and January; the CO 2 concentrations in August; and the CO 2 emission rates in December) between these two rooms for each measuring month did not differ significantly (P Ͼ 0.05). The measured gas concentrations were generally below the permissible exposure limits (PELs) established by the Occupational Safety and Health Administration (OSHA) throughout the year except for the NH 3 concentrations in cold weather (December, January, and February). INTRODUCTIONAmmonia (NH 3 ), hydrogen sulfide (H 2 S), carbon dioxide (CO 2 ), and odorous gaseous compounds produced in livestock facilities and manure storage units are a great concern in Canada because of their environmental and health effects on animals, workers, and nearby residents, as well as social and economic impacts on animal industry and local communities. 1,2 Over the last decade, some abatement methods and strategies such as biofiltration, diet manipulation, manure storage covers, vegetative environmental buffers, wet scrubbers, biocurtains, and ultraviolet (UV) light treatment have been developed and utilized to alleviate odor and gas problems. However, few of these technologies are adopted by swine producers because of relatively low efficacy and high implementation costs. 3 Recently, a common approach widely practiced is to maintain adequate setback distances between the livestock operation and the neighboring residences. To determine science-based setback distance, air dispersion models have been used to estimate downwind odor and gas concentrations from animal feeding operations. 4 -6 A good prediction of downwind odor and gas concentrations using air dispersion models relies largely on source emission rate information, which is highly variable with diurnal and seasonal variations, building characteristics, ventilation rates, animal size and density, weather conditions, and manure handling systems, to name a few. In the literature, large variability in odor and gas concentrations and emissions from different s...

Background Lack of sustainable access to clean drinking water continues to be an issue of paramount global importance, leading to millions of preventable deaths annually. Best practices for providing sustainable access to clean drinking water, however, remain unclear. Widespread installation of low-cost, in-home, point of use water filtration systems is a promising strategy. Methods We conducted a prospective, randomized, controlled trial whereby 16 villages were selected and randomly assigned to one of four treatment arms based on the installation location of Sawyer® PointONE™ filters (filter in both home and school; filter in home only; filter in school only; control group). Water samples and self-reported information on diarrhea were collected at multiple times throughout the study. Results Self-reported household prevalence of diarrhea decreased from 25.6 to 9.76% from installation to follow-up (at least 7 days, and up to 200 days post-filter installation). These declines were also observed in diarrhea with economic or educational consequences (diarrhea which led to medical treatment and/or missing school or work) with baseline prevalence of 9.64% declining to 1.57%. Decreases in diarrhea prevalence were observed across age groups. There was no evidence of a loss of efficacy of filters up to 200 days post-filter installation. Installation of filters in schools was not associated with decreases in diarrhea prevalence in school-aged children or family members. Unfiltered water samples both at schools and homes contained potential waterborne bacterial pathogens, dissolved heavy metals and metals associated with particulates. All dissolved metals were detected at levels below World Health Organization action guidelines. Conclusions This controlled trial provides strong evidence of the effectiveness of point-of-use, hollow fiber membrane filters at reducing diarrhea from bacterial sources up to 200 days post-installation when installed in homes. No statistically significant reduction in diarrhea was found when filters were installed in schools. Further research is needed in order to explore filter efficacy and utilization after 200 days post-installation. Trial registration ClinicalTrials.gov, NCT03972618. Registered 3 June 2019—retrospectively registered.

No abstract