Sulfur dioxide Can impair respiratory function and aggravate existing respiratory diseases causing severe distress and cardiac illnesses. Non-respirable suspended particles Larger particles that are not absorbed into the lungs. They mainlny cause aesthetic problems such as soiling, dust, soot, etc. Respirable suspended particulates Smaller than 10 millionths of a metre. Can penetrate deep into the lungs and cause respiratory problems. Also affects visibility. Fine particulate matter Smaller than 2.5 millionths of a metre. The smaller the particle, the deeper it can penetrate into the respiratory system and the more damage it causes. Nitrogen dioxide Lowers a person's resistance to respiratory infections and aggravates existing chronic respiratory diseases. Carbon monoxide Reduces amount of oxygen delivered to the body's organs and tissues. Causes shortness of breath, chest pain, headaches and loss of co-ordination. Ozone Can cause irritation to the eyes, nose and throat. High doses can aggravate existing respiratory illnesses such as asthma. Lead Can cause lower IQ and hearing impairments in children. Affects blood pressure, kidneys, and nervous, immune, cardiovascular, and reproductive systems. Volatile organic compounds Precursor pollutants, such as solvents, that help form ground-level ozone and particulate matter. Carbon dioxide Contributes to global warming. Hotter temperatures increase levels of cardiovascular problems, heat exhaustion and respiratory problems.