SOARING levels of pollution and Saharan dust is expected to blast across southern England tomorrow (Friday), experts have warned.
Britain is expected to enjoy the hottest day of the year so far, with temperatures of up to 21C predicted.
However, the high pressure causing the warmer temperatures will bring with it higher levels of pollution (indicated by red on the map above).
A spokeswoman for The Department for Environment, Food and Rural Affairs (DEFRA), said:"Locally generated air pollution, combined with pollution from the continent and Saharan dust, could cause high or very high levels on Friday.
"This is expected to clear on Saturday and pollution levels will return to low throughout the morning."
The DEFRA website says: "Levels of air pollution are forecast to become High in many areas of central, eastern and northern England, with locally Very High levels forecast for a time in the far southeast of England.
"This is due to a combination of pollutants trapped near the ground, a light southeasterly flow bringing additional pollutants from the continent and, in addition, a small amount of Saharan dust in the air. Across the rest of the United Kingdom, levels of air pollution are expected to be mainly Moderate."
Meanwhile, Asthma UK is warning parents of children with asthma to take extra care.
Its website says: "Pollution levels and tree pollen levels are both rising today – and forecast to be even higher tomorrow. Poor air quality and pollen allergy can both trigger asthma symptoms, and increase the chance of a potentially life-threatening asthma attack.
"Children can be more affected by pollution because they have faster breathing rates, and their lungs are still developing."
It also gives advise on how to protect yourself, including making sure you take asthma medicines. making sure you have your reliever inhaler with you at all times and avoiding outdoor exercise and time outdoors, especially near busy polluted roads or in parks, gardens or woodlands where there are birch, ash, elm, hazel and alder trees.