Thursday’s column reviewed the history of car air conditioning, dating back to 1933; further advanced from 1940 to 1952.

Vehicle components emit a cancer-causing carcinogen called benzene that rapidly increases when parked cars are exposed to sunlight. Car manufacturers suggest vacating the internal heat by opening windows first and activating the air conditioning, second.

As stated in a previous column, a reader noted that researchers at Exxon-Mobil are extracting citrus oil from orange and lemon peels to eliminate Benzene in vehicles.

The implementation of a hydrocarbon substitute involves manipulating molecules similar to polymer processing. Dashboards, steering wheels and seat covers of the past will have citrus components in the future.