Air pollution levels increased in Istanbul as of Tuesday while acid rain is predicted for the city Thursday and Sunday, an expert warned.

Dr. Deniz Demirhan from the Department of Meteorology of Istanbul Technical University warned that high pressure in the air contributed to the pollution and urged the public to stay indoors for the least impact from the pollution.

Demirhan said PM10 values for the city, which should be 50 micrograms at most, reached 189 micrograms Tuesday.

"We expect a strong, high pressure until Thursday. There is already pollution but it is not felt intensely, except when the weather has high pressure. Invisible pollution or pollution caused by particles are more dangerous on such days," Demirhan said.

She also warned about acid rain. "Currently, we have a polluted atmosphere and any precipitation will be acid rain and will bring down pollutants to the ground. It will clean the air but we will see the acid rain's impact on the ground, such as corrosion on metals, asphalt and damage to our skin and hair," she said.