Some of the environmental concerns of the U.K. involve air pollution from gasoline and diesel-powered vehicles. Air pollution also blackens buildings and threatens wildlife. As far back as the 1300s, smog was a constant problem. King Edward I created smokeless zones in London, where only smokeless fuels could be burned. Today, the government has set limits on industry. Lawmakers have created laws that demand vehicles be manufactured to produce less harmful exhaust. Cleaner coals, increased use of electricity, and the use of gas have reduced air pollution. However, air pollution still causes acid rain which affects many countries in Western Europe.