This picture from Nigeria represents a national and international health hazard

On April 11 2006 the Federal Court of Nigeria ordered the Shell Petroleum Development Company of Nigeria Limited (Shell Nigeria and the Nigerian National Petroleum Corporation (NNPC)) to cease gas firing in Nigeria by April 2007. They were to appear in Court on May 31 with a detailed plan about how this was to be done.  The Nigerian Government Minister of State for Petroleum was also ordered to appear in Court on that date.  Previously in November 2005, a lower Court had found in favour of local resident Jonah Gbemre and the Iwherekan (Nigerian) community.    It was held that gas flaring was a violation of Article 33 of the Nigerian Constitution (the fundamental right to life) and Article 34 (the right to dignity).  A violation of the African Charter on Human and Peoples’ Rights also was held to have occurred, including the right of a person to have the best attainable state of physical and mental health (Article 16) and the right of people to an environment favourable to their development (Article 24).  This is a substantial decision because more gas is flared in Nigeria than in any other country in the world, with substantial property damage and health threats to Nigerian communities.

Gas flaring burns off petroleum gases that emerge from oil wells. These gases are a health issue because they produce thousands of tons of carbon dioxide a greenhouse gas without any return such as generation of electricity to humanity.

They are thus a cause of the many health problems caused by climate change.
In Nigeria they are a cause of morbidity and mortality from respiratory disease.