According to a report by North America's environmental watchdog agency there is an increase in the rates of childhood asthma in Canada. Statistics shows one out of every ten children are diagnosed with the respiratory illness.
Asthma is one of the most common prevalent chronic conditions in Canadian children. It also affects the adults. This study is conducted by federal government researchers keeping in mind the health of children in Canada, the United States and Mexico.
The disease has characteristic features such as wheezing and chest pain. It is prevalent among the children in North America. Statistics show that about one million children in Canada have or have had asthma.
Statistics taken in 2003 said that Canadian boys aged 8 to 11 wee suffering from asthma out of which 20% were diagnosed with the disease in the late 1990s. In the United States, about 13 per cent of children had asthma at some point in their lives.
Researchers are not aware of the exact cause of asthma, but say that it is linked to indoor and outdoor air quality.
Children are affected by the change in the air quality because of their developing body systems and higher intakes of air. Exposure to passive smoking, dust mites, pesticides, the fumes given off by some plastics, and volatile organic compounds in solvents and other chemicals may also play a role in the development of asthma.
Research scientist Teresa To at Toronto's Hospital for Sick Children said that the quality of indoor air is very important as children spend about 80 per cent of their time indoors.
She said the extremely high asthma rate in boys just before their teenage years may be because of the increased time they spend outdoors during playing and perform heavy exercise and hence they are prone to wheezing which eventually progresses to asthma.
The causative agents present in the outdoor air that are suspected in asthma include ground-level ozone and small particulates. It is also said that about a quarter of Canadian residents live in homes built before the 1960s and may be exposed to excessive levels of lead, which was the common ingredient in paint. Hence Health Canada is testing the lead levels in about 5,000 people.
A number of cancers are also on the rise among the young adults, which may be related to childhood exposures to environmental hazards.
Young Canadian adults have increased rates of thyroid cancer, which is due to exposure to medical X-rays; melanoma due to sun exposure early in childhood; testicular cancer and non-Hodgkin's lymphoma which could be attributed to the various environmental factors.