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The concentrations of carbon dioxide in the atmosphere are expressed as parts per million by volume (abbreviated as ppmv, or ppm(v), or just ppm). To convert from the usual ppmv units to ppm mass (abbreviated as ppmm, or ppm(m)), multiply by the ratio of the molar mass of CO 2 to that of air, i.e. times 1.52 (44.01 divided by 28.96).
An air quality index (AQI) is an indicator developed by government agencies [ 1 ] to communicate to the public how polluted the air currently is or how polluted it is forecast to become. [ 2 ][ 3 ] As air pollution levels rise, so does the AQI, along with the associated public health risk. Children, the elderly and individuals with respiratory ...
Regulations and standards from around the world show that CO 2 levels below 1000 ppm represent good IAQ, between 1000 and 1500 ppm represent moderate IAQ and greater than 1500 ppm represent poor IAQ. [82] Carbon dioxide concentrations in closed or confined rooms can increase to 1,000 ppm within 45 minutes of enclosure. For example, in a 3.5-by ...
Another study observed a decline in basic activity level and information usage at 1000 ppm, when compared to 500 ppm. [ 53 ] However a review of the literature found that a reliable subset of studies on the phenomenon of carbon dioxide induced cognitive impairment to only show a small effect on high-level decision making (for concentrations ...
pCO2, pCO2, or is the partial pressure of carbon dioxide (CO 2), often used in reference to blood but also used in meteorology, climate science, oceanography, and limnology to describe the fractional pressure of CO 2 as a function of its concentration in gas or dissolved phases. The units of p CO 2 are mmHg, atm, torr, Pa, or any other standard ...
The term immediately dangerous to life or health (IDLH) is defined by the US National Institute for Occupational Safety and Health (NIOSH) as exposure to airborne contaminants that is "likely to cause death or immediate or delayed permanent adverse health effects or prevent escape from such an environment." Examples include smoke or other ...
e. Air pollution is the contamination of air due to the presence of substances called pollutants in the atmosphere that are harmful to the health of humans and other living beings, or cause damage to the climate or to materials. [ 1 ] It is also the contamination of the indoor or outdoor environment either by chemical, physical, or biological ...
On average, exposures at 100 ppm or greater is dangerous to human health. [23] The WHO recommended levels of indoor CO exposure in 24 hours is 4 mg/m 3 . [ 24 ] Acute exposure should not exceed 10 mg/m 3 in 8 hours, 35 mg/m 3 in one hour and 100 mg/m 3 in 15 minutes.