(AP) — Officials have issued a health advisory for Lancaster County because of high level of smoke from agricultural burning in the Midwest.

The Lincoln-Lancaster County Health Department issued the advisory Friday for people with asthma, lung disease and other respiratory conditions or heart disease. Individuals with those conditions should stay indoors and avoid strenuous physical activity if the air becomes smoky.

Chris Schroeder, air quality program supervisor for the department, says people may be exposed to smoke this weekend from extensive burning in the Midwest, especially the Flint Hills area of Kansas. There may be winds from the south.

Officials say most people’s health will not be affected.