* Dubai, Doha, Abu Dhabi downwind of Bushehr nuclear plant
* GCC says Iran has not responded to concerns raised over safety
National emergency officials in the Gulf Cooperation Council (GCC) countries met on Sunday in Saudi Arabia to discuss the risk of radiation spreading over the Gulf if Iran's Bushehr nuclear power plant is damaged by another earthquake.
A 6.3-magnitude earthquake struck close to Iran's only nuclear power station last week, killing dozens of people but leaving the nearby plant undamaged, according to Iranian officials and the Russian company that built it.
There is no indication of any radiation leak following last week's tremor and the head of Iran's Atomic Energy Organisation said the plant was built to withstand much bigger quakes.
But the plant on earthquake-prone Iran's southern coast is a growing worry for its neighbours, because the prevailing winds of the Gulf mean that if radiation ever does escape it would probably be blown over the Qatari capital Doha and the main oil exporting ports of the United Arab Emirates.
GCC Secretary-General, Abdulatif al-Zayani, said that Gulf Arab states must have a joint plan to collectively deal with any possible leak from the Iranian facility.
"The earthquake that the Iranian city of Bushehr was subject to has raised a great deal of concern among GCC countries and the international community of a possible damage to the Bushehr nuclear reactor that could causing a radioactive leak, God forbid," Zayani said at the start of the meeting in Riyadh.
"The GCC countries have previously warned against the danger of the nuclear reactor of Bushehr and the possible nuclear leak and its harmful effect on the environment in the Gulf," he added.
Zayani said and the six Gulf Arab states have previously urged Tehran to ensure its facility complies with international safety standards and join the Convention on Nuclear Safety, but Tehran did not show any sign it understood international concerns over its nuclear programme.
Iran is the only country operating a nuclear power plant that does not belong to the convention, negotiated after the 1986 nuclear disaster in Chernobyl which contaminated a wide area and made 160,000 Ukrainians homeless.
Western countries have imposed sanctions on Iran over its wider nuclear programme, which they say could include weapons. Tehran says its programme is for peaceful purposes only.
Saudi oil export ports could be spared by prevailing winds carrying any fallout further east over Qatari gas export facilities, UAE oil ports and big cities Abu Dhabi and Dubai.
Most nuclear plants are designed to withstand earthquakes and shut down safely if there is a major earth movement.
In March 2011 a 9.0 magnitude earthquake shook Japan, causing four nuclear power plants to shutdown their 11 reactors, as designed. But a subsequent tsunami destroyed back-up generators at one of them, Fukushima, causing its cooling system to fail and three of the reactors to melt down.
Iran sits on major fault lines and has suffered several devastating earthquakes, including a 6.6-magnitude quake in 2003 which flattened the southeastern city of Bam and killed more than 25,000 people.
The GCC countries are the UAE, Bahrain, Saudi Arabia, Oman, Qatar and Kuwait.