The nonmedical use of prescription opioids is a major public health issue in the United States, both because of the overall high prevalence and because of marked increases in associated morbidity and mortality. In 2014, a total of 10.3 million persons reported using prescription opioids nonmedically (i.e., using medications that were not prescribed for them or were taken only for the experience or feeling that they caused).

Nitrous oxide (N2O) is the predominant ozone-depleting substance and contributes approximately 6% to overall global warming. Terrestrial ecosystems account for nearly 70% of total global N2O atmospheric loading, of which at least 45% can be attributed to microbial cycling of nitrogen in agriculture. The reduction of N2O to nitrogen gas by microorganisms is critical for mitigating its emissions from terrestrial ecosystems, yet the determinants of a soil’s capacity to act as a source or sink for N2O remain uncertain4.