By law, heavy lorries have to be fitted with equipment to reduce the amount of the dangerous NOx gas that they emit when driven on the country’s roads.

However, it seems as if at least one in four have apparatus that disables the filters fitted in order to save money, DR Nyheder reports.

NOx is a gas that results from the combustion of nitrogen and oxygen at high temperatures – for example, in the diesel engine of a lorry. It is hazardous to people, especially to those with heart or lung conditions, and can cause breathing difficulties, reduced lung functionality, headaches, irritation of the eyes and loss of appetite.

Gassing up or gassing out
Checks carried out by police on the motorways of southern Jutland over Easter found that around 25 percent of lorry drivers were flouting the rules by disabling the filters.

“If you cheat when it comes to emissions, you pollute much more than the permitted level,” said Sara Røpke from the Danish environmental protection agency, Miljøstyrelsen.

It is a matter of hard cash as lorry owners can save around 10 øre per kilometre if they disable the filter.

Lasers to the rescue?
A new advanced measuring system using lasers that the agency has up its sleeve may change all that. A system being installed at two selected locations on the Danish motorway network, in an effort to find out exactly how serious the problem is, will run until the New Year. In addition, the agency is looking at whether to raise the level of fines for infractions.

“It’s really important that vehicles are fitted with filters so that we are subjected to as little NOx pollution as possible. It is dangerous and has a negative effect on our health,” said Røpke.