Persistence of elevated concentrations of PM, affiliated pharmaceuticals, and tetracycline resistance genes downwind of feedyards.
Environ Pollut
; 247: 467-473, 2019 Apr.
Article
em En
| MEDLINE
| ID: mdl-30690243
ABSTRACT
Beef cattle feedyards have been identified as sources of large amounts of particulate matter (PM) which may transport affiliated chemicals including steroids, beta agonists, and antibiotics from feedyards into the environment. This study is the first to examine persistence of PM-affiliated pharmaceuticals downwind of feedyards using multiple downwind samples collected at increasing distances from feedyard boundaries (nâ¯=â¯5). Concentrations of antibiotics and ractopamine per gram of PM remained consistent at all downwind locations (out to 4.8â¯km) whereas concentrations per m3 air decreased significantly at distances between 0.1 and 0.7â¯km downwind, corresponding to significant decreases in mass of PM. Monensin was present in the highest concentrations of any measured pharmaceutical, with concentrations of 37⯵g/g PM (376â¯ng/m3) air in samples collected within 0.1â¯km downwind of feedyards. Total copy count of tetracycline resistance genes (tetW, tetQ, tetO, tetM, tetL, and tetB) were also significantly increased in samples collected within 0.1â¯km downwind of feedyards (106 copies) as compared to samples collected upwind (103 copies) and farther downwind (104 copies) of feedyard boundaries. These results suggest that transport of pharmaceutical-laden PM into the terrestrial environment is occurring primarily via PM deposition within 0.7â¯km of the feedyard, while aerial transport persists over longer distances (>4.8â¯km).
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MEDLINE
Assunto principal:
Resistência a Tetraciclina
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Monitoramento Ambiental
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Poluentes Atmosféricos
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Material Particulado
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Genes Bacterianos
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Antibacterianos
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article