Studies have shown that sunlight coming in through side windows of vans is probably responsible for an increase in the disease.
The side windows block UVB rays that cause sunburn but not the deeper penetrating UVA rays that cause cancer. Laminated screens blocks both rays.
The studies were carried out at the St Louis University School of Medicine, which looked at 898 patients with skin cancer on the left side of their bodies.
The rate of cancers directly matched the time that people sat in vehicles.
Report author Dr Scott Fosko said: ‘This finding supports out theory that drivers who regularly spend many hours in a vehicle are more likely to develop skin cancer on the left side of the body.’
Drivers in the UK, of course, would be affected on right side. Dr Fosko called on van makers to fit tinted glass to side screens or use UV filters.
A spokesman for Cancer Research UK added: ‘If you are driving long distances or even sitting in a conservatory for long periods, you are putting yourself at risk. It is important to take care whenever you are exposed to the sun.’