THE BASIC CONCEPTS OF ALLERGIES: ENGINE EXHAUSTS

For the chemically susceptible, the worst kind of engine exhaust is that of diesels. Diesel exhaust is particularly aggravating to many susceptible individuals and if encountered in the course of driving can represent a real traffic hazard.

Busses using diesel fuel can be troublesome for passengers or those riding in other vehicles. Moving vehicles generally tend to suck in their own exhaust fumes if the windows are open. Therefore if a passenger rides in the rear of the bus, he is more likely to be exposed to these fumes than if he stays in the front of the passenger compartment. One patient with a relatively mild form of the chemical-susceptibility problem reported that he enjoyed riding in the back of the bus with the window open. He found this a stimulating experience, although he had no idea why. Afterwards, however, he noticed a feeling of depression. This appears to have been an addictionlike response to chemical fumes.

Sometimes busses follow each other in a caravan. In these cases, the exhaust of one bus is swept up into the passenger compartment of the next, especially if the wind is traveling in the same direction as the fumes.

Passengers often develop headaches and other reactions, such as nausea, during or following bus trips, without ever suspecting exhaust fumes as the cause. These effects can be cumulative, occurring after the passengers have been riding in the vehicle for a certain number of miles or minutes. In less susceptible people, the symptoms may only come on if the bus is in poor repair or if the rear windows are left open.

Often the effects of diesel fumes are subtle and go unnoticed. For instance, the fatigue associated with riding the bus downtown to go shopping is frequently out of proportion to the actual amount of activity involved. Much of this exhaustion often stems from the fumes of busses and from general traffic pollution.

In railroad stations, the diesel fumes are greatest at the entrances and exits. This is especially true of underground or covered stations in which passengers are forced to walk past a line of “purring” locomotives to reach their coach or the station exit. Some patients have become acutely ill whenever they have attempted to run such a gauntlet. Other than this, however, diesel trains actually provide less troublesome exposure than busses or automobiles, especially during rush-hour traffic. The reason for this is the rapid speed of the trains, the avoidance of traffic jams, and the relative isolation of the passenger compartment from the source of pollution.

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