Another sandstorm that descended Monday on climate-stressed Iraq sent at least 4,000 people to hospital with breathing problems and led to the closure of airports, schools and public offices across the country.It is the eighth dust storm since mid-April to hit Iraq, which has been battered by soil degradation, intense droughts and low rainfall linked to climate change.The last one earlier this month led to the death of one person, while more than 5,000 others had to be hospitalised for respiratory problems.