This document discusses carbon monoxide (CO), including its properties, sources, and effects on human health and the environment. It notes that CO is a colorless, odorless gas produced through natural processes and human activities like burning fossil fuels. In humans, CO reduces the blood's ability to carry oxygen by forming carboxyhemoglobin. Exposure to CO can be harmful even at low concentrations. The document also mentions carbon dioxide (CO2) as a greenhouse gas increasing due to fossil fuel combustion and deforestation. It identifies the eight major air pollutants regulated by the EPA.

1. Rahul Kamble

2. It is colourless, odourless and tasteless gas
Chemically inert (non-reactive) under normal
conditions
Atmospheric mean life of about 2.5 months
About 53% of CO emissions are from anthropogenic
in origin

3. About 3.5 billion tonnes/year of CO produced by
oxidation of methane gas from decaying vegetation
A resting human’s exhalations contain approx. 1 ppm
of CO; which comes out to be 2.9 tonnes/day OR 1058
tonnes/year in USA
Transportation source—primarily petrol powered
combustion engines
Fuel combustion in stationary sources, industrial
sources and solid-waste disposal

4. CO reacts with Hemoglobin (Hb) of the blood to form
carboxyhemoglobin (COHb)
COHb reduces the oxygen carrying capcity of blood
Hb has great affinity for CO; around 200 times more
than O2 thus even in small conc. is harmful
CO conc. are especially high in congested urban areas
were traffic is heavy and slow moving

5. CO2 is a important green house gas
Due to burning of fossil fuels and cutting of forest
Atmospheric CO2 is usually measured in terms of its
concentration relative to all other gases in ppmv
(parts per million by volume)
Pre industrial conc. was approx. 280 ppmv and
present is approx. 400 ppmv

6. Fossil fuels  5 Gt/year
Oxidation of plant tissues, litter and soil carbon,
cutting of forest 0-2 Gt/year
From atmosphere to ocean  4 Gt/year
Effects
Global warming

7. There are eight criteria pollutants
Carbon monoxide
Oxides of nitrogen (NO nitric oxide, NO2 nitrogen
dioxide, NO3 nitrogen trioxide, N2O nitrous oxide,
N2O5 nitrogen pentaoxide, HNO2 nitous acid, HNO3
nitric acid)
VOC’s (Volatile Organic Compounds)
Sulphur oxides (SOx) (SO2 and SO3)
Particulate matter (PM10 and PM 2.5)
Hydrocarbons

8. Ground level ozone
Lead
Why they are called so?
“ the original ambient air quality standards for these
pollutants were based on extensive documentation
assembled and published by EPA (Environmental
Protection Agency USA) in a multivolume set of Air
Quality Criteria documents, from which the name
criteria pollutants originated”.