The Thai government struck a deal with the Federation of Thai Industries (FTI) on Tuesday to give discounts for diesel engine maintenance services in a bid to bring down the increasing levels of fine particulate matters (PM2.5) in the country.

"The discount to fix, repair or maintenance of diesel engine is effective immediately," Environment Minister Warawut Silpa-archa said, adding that owners of cars which have been on the road for at least seven years will be entitled to a discount of 20 to 30 percent, and 50 percent for cars over 15 years old.

Owners of vehicles more than 20 years old will also be entitled to discounts on spare parts of 20 to 50 percent, the minister said.

The FTI also said that companies that are taking part in the project include Toyota, Mitsubishi, Isuzu, Nissan, Ford, Hino and Suzuki.

Minister Warawut said aging diesel cars were a major source of PM2.5 particles, so encouraging regular maintenance could help reduce pollution.

Unfortunately, Thailand has no laws yet to phase out old cars, the minister said.

The Ministry of Natural Resources and Environment had earlier announced the national goal to reduce PM2.5 levels by 20 percent by eliminating bush fires, which the minister said, is a major cause of air pollution in the northern region and cities, including Chiang Mai.

Warawut said Bangkok is very polluted as a result of exhaust fumes from vehicles, especially vehicles that run on old diesel engines.