Throughout the U.S., asthma allergies appear to be getting worse.

However, medical experts do not believe that increasing asthma allergies are the result of more plant pollination. Instead, they blame these allergies on the increased levels of diesel fumes and ozone in the air.

City dwellers appear to be most affected by the rise in allergies. This is because there is increasing evidence that air pollutants worsen allergies, and urban areas tend to be meccas for air pollution.

As a result of this trend, those suffering from allergies must pay attention not only to pollen counts, but to the pollution index as well. People with allergies may decide to postpone outdoor sports activities because of increased air pollutants.

Medical research indicates that ozone can worsen these allergies. For instance, ozone results in chronic inflammation of the airways of those suffering from these allergies and related problems. As a result, people with allergies often show up in a hospital emergency room a few days after a high ozone day.

If an individual's allergies include sensitivity to pollen, he or she may find that diesel exhaust tends to make the condition worse. As a result, it's best for those with asthma allergies to limit their exposure to pollutants by venturing out in the morning rather than the afternoon, when allergens are greatest.

Another option for those with allergies is to scale down their exercise routine. By walking rather than running, they will slow down their breathing, decreasing the chance that their allergies will get the best of them. Experts say some of the worst air for those with allergies is on or near freeways.

If you experience allergies, you may think that you lessen your risk of an asthma attack by using your car's air conditioner. However, medical experts say most cars do not have a filtration system for small particles, so the air conditioning will have no effect on your allergies.