All news on the topic: Toxic smog

Emergency services were still on the scene near Teutopolis, Illinois, to try and contain the cloud of anhydrous ammonia that emanated from the overturned tanker late Friday evening

A second wave of northerly winds has wildfire smoke billowing into the US from Canada once again — and this time, it's hitting Chicago the hardest

Americans have started masking again amid the wildfire smoke drifting across the Canadian border. Experts are weighing in on the effectiveness of the devices

New York City Public Schools has asked pupils to stay home tomorrow as smoke from the wildfires in Canada continue to affect swathes of the US including major cities

The maps show the spread of smoke across the US as wildfires in Canada continue to rage. The FAA has been forced to temporarily ground flights as visibility makes safe take off impossible

The truck carrying toxic nitric acid overturned on the I-10 in Arizona, US, sending a cloud of gas into the air which could be seen five miles away