The Mexican government says air pollution and smoke from forest fires are costing the country millions of dollars a day in lost industrial production and extra costs in health care.

The government said emergency measures cutting the number of cars on the road and reducing factory output meant lost sales ofeight-million dollars a day.

In addition, the costs of dealing with a sharp increase in health complaints due to smog was costing three-and-a-half-million dollars a day in Mexico City alone.

Emergency conditions to combat the smog are continuing in Mexico City for a fourth day. .