Sandstorms have engulfed the Middle East in recent days, in a phenomenon experts warn could increase because of climate change, putting human health at grave risk. At least 4,000 people went to hospital Monday for respiratory issues in Iraq where eight sandstorms have blanketed the country since mid-April.

The phenomenon has also smothered Iran, Kuwait, Saudi Arabia and the United Arab Emirates with more feared in the coming days. The World Meteorological Organization has warned of the "serious risks" posed by airborne dust. The fine dust particles can cause health problems such as asthma and cardiovascular ailments, and also spread bacteria and viruses as well as pesticides and other toxins. "Dust particle size is a key determinant of potential hazard to human health," the WMO said.