Common air pollutants, which are present in car exhaust fumes, may contribute to the development of hay fever like symptoms in children, according to a new study published in Respiratory Research.

The study of more than 32,000 school children in Taiwan, found that increased exposure to traffic pollutants including carbon monoxide and nitrogen oxides significantly increased a child’s risk of developing allergic rhinitis.

The international team from the University of Birmingham’s Institute of Environmental and Occupational Medicine and the National Cheng Kung University in Taiwan, monitored school children’s exposure to nitrogen oxides, carbon monoxide, sulphur dioxide and ozone, in 22 centres across Taiwan. The 32,134 children involved were chosen from schools within one kilometre of an air monitoring centre, to ensure the levels of chemical exposure were accurately assessed.

More than 25% of the children (8,202) had allergic rhinitis diagnosed by a doctor. The team found that the risk of allergic rhinitis was related to the average annual levels of nitrogen oxides, carbon monoxide (which are common in vehicle emissions) and sulphur dioxide in each residential area. This indicates that exposure to air pollutants from traffic exhausts and other combustion sources may play a role in causing allergic rhinitis.

The annual average of nitrogen oxides ranged from 10 to 44 ppb (parts per billion) in the studied areas. The data collected showed the risk of allergic rhinitis increased approximately 10% for each 10 ppb increase in the levels of nitrogen oxides. The levels of sulphur dioxide in the air were considerably lower than levels of nitrogen oxides: ranging from 0.3 to 10 ppb. However, there was an estimated 15% increase in the risk of allergic rhinitis per 10 ppb increase in sulphur dioxide levels. The research also showed that a familial history of the condition had a significant impact on levels of allergic rhinitis.

Professor Jouni Jaakkola, Director of the University of Birmingham’s Institute for Occupational and Environmental Medicine explains: “Allergic rhinitis is an extremely common condition, which is on the increase in many countries. Although the symptoms are not dangerous, they are unpleasant and disruptive for many people. They can influence daily activities and may even limit the choice of future career.”

“These findings strengthen the evidence that exposure to pollutant chemicals can have a significant impact on a child’s likelihood of developing allergic rhinitis. Development of allergic rhinitis often precedes development of asthma, a more serious chronic disease. We reported last May that also the risk of asthma is related to air pollution levels, so this research helps to build on those results.”



For further information contact Ben Hill, University of Birmingham Press Officer, telephone 0121 414 5134 or 07789 921163

The Study: Relation between air pollution and allergic rhinitis in Taiwanese schoolchildren is published in Respiratory Research


The research links staff from the University of Birmingham’s Institute for Occupational and Environmental Medicine with Cheng Kung University in Taiwan and China Medical University.


Allergic rhinitis is the medical term for Hay Fever like symptoms that mimic a chronic cold. Many substances cause the allergic symptoms in hay fever. Allergic rhinitis is the correct term for this allergic reaction.

Symptoms include nasal congestion, a clear runny nose, sneezing, nose and eye itching, and tearing eyes. Loss of smell is common and loss of taste occurs occasionally.

The Institute of Occupational and Environmental Medicine

The University of Birmingham started to work in this area 70 years ago with the establishment of the Department of Industrial Hygiene and Medicine, and has changed emphasis along with changes in working life from the industrial revolution to today’s mobile and dynamic workplace. As we are interested in the how the environment as a whole affects human health there is now more synergy between occupational and environmental health in research and teaching.