Carbon monoxide (CO)
Is a colorless, odourless gas that interferes with oxygen availability throughout the body.

Exposed individuals and physicians may not recognize some symptoms as CO poisoning due
to their similarity with viral illnesses such as influenza.

Individuals with heart disease, chronic respiratory ailments, such as emphysema, and anaemia,
and foetuses, infants, and young children have an increased susceptibility to CO poisoning.

Low levels of CO can cause fatigue and chest pain in people with chronic heart disease.

As CO exposures increase, symptoms progressively worsen through headaches,
drowsiness, nausea, vomiting, confusion and disorientation.

At very high CO exposures, loss of consciousness and death are possible.

Nitrogen dioxide
Can irritate the skin and the mucous membranes in the eyes, nose and throat.

Depending upon the level and duration of exposure, respiratory effects range from slight
irritation to burning and chest pain, coughing, and shortness of breath.

In addition, repeated exposure to elevated levels of nitrogen dioxide may contribute to bronchitis.

Children who are exposed to low levels of nitrogen dioxide, often show increased
susceptibility to respiratory infections.

Others who may be especially sensitive to nitrogen dioxide exposure include people with
chronic respiratory disease including bronchitis, asthma and emphysema.