Exhaled carbon monoxide levels correlate with incidence of oral mucosal lesions independent of smoking status

Photocatalytic purification of contaminated air in intensive care units by ZnSn(OH)6 nanoparticles

The air purification in intensive care units (ICU) involving the removal of smog and volatile organic compounds (VOCs), disinfection, and sterilization are closely linked to important health issues. The environmental photocatalysis technology that could decompose gaseous pollutants into small molecular inorganic substances provides the potential solution. In a chamber of 30-m³ simulated ICU, photocatalytic purifier with ZnSn(OH)₆ nanoparticles photocatalyst is set up to treat 10 VOCs with concentration below 2 ppm. Compared with regular purifiers of plasma and activated carbon, the present photocatalytic purifier can completely eliminate 10 varieties of low-concentration irritating VOCs without CO production. The continuous tests show that loading of 600 g ZnSn(OH)₆ has capacity to treat large volumes of VOCs and remains high removal efficiencies up to 600-h operation. The results suggest that the photocatalytic purifier could be potentially applied for the treatment of contaminated indoor air particularly ICU. The mechanism of ZnSn(OH)₆ photocatalysis is proposed to interpret the high performance and mineralization of the degradation process.

A brief history of carbon monoxide and its therapeutic origins

It is estimated that 10% of carbon throughout the cosmos is in the form of carbon monoxide (CO). Earth's earliest prebiotic atmosphere included the trinity of gasotransmitters CO, nitric oxide (NO), and hydrogen sulfide (H₂S), for which all of life has co-evolved with. The history of CO can be loosely traced to mythological and prehistoric origins with rudimentary understanding emerging in the middle ages. Ancient literature is focused on CO's deadly toxicity which is understandable in the context of our primitive relationship with coal and fire. Scientific inquiry into CO appears to have emerged throughout the 1700s followed by chemical and toxicological profiling throughout the 1800s. Despite CO's ghastly reputation, several of the 18th and 19th century scientists suggested a therapeutic application of CO. Since 2000, the fundamental understanding of CO as a deadly nuisance has undergone a paradigm shift such that CO is now recognized as a neurotransmitter and viable pharmaceutical candidate. This review is intended to provide a brief history on the trace origins pertaining to endogenous formation and therapeutic application of CO.