Tehran, May 22, IRNA � Head of Iran's Department of the Environment Masoumeh Ebtekar said that the regional instability has hindered efforts made to settle the particulate matters.

Talking to IRNA, Ebtekar made the remarks before leaving Bangkok on late Thursday.

Ebtekar was in Thailand to attend an expert meeting on environment.

She underlined that the ways for fostering environmental cooperation also were discussed between Iran, Thailand, The Philippines and South Korea during the meeting.

Particulate matters are tiny pieces of solid or liquid matter associated with the Earth?s atmosphere. Sources of particulate matter can be manmade or natural.

By IRNA