NAIROBI, Sept. 20 - The transport sector is a major contributor to air pollution in Africa, a UN Environment (UNEP) official said on Thursday.

Juliette Biao Koudenoukpo, the UN Environment regional director for Africa, attributed the situation to the importation of fuel inefficient second-hand vehicles, inadequate vehicle import regulation policies and the low purchasing power among the population.

"African countries need to put in place air quality standards to help inform their policies," said Koudenoukpo during a forum in Nairobi on transforming mobility in Africa through innovative solutions.

She said the transport sector has been identified as a major source of greenhouse gas emissions and other pollutants that have significant effects on the environment and health.

The UNEP official said in an effort to provide adequate transport infrastructure and services, many African governments are giving rise to unregulated transport systems that further complicates the quest for clean air.

She said the UN Environment is taking a leading role through research, innovation and implementation of programs that seek to tackle poor air quality.

A number of African countries like Cote d'Ivoire have developed air quality standards, and sought to further develop their monitoring capacity.

Coletha Ruhamya, director general of Rwanda Environmental Management Authority, said a 2017 study showed that motorcycles contribute 51 percent to air pollution in the country.

She said the Rwandan government is promoting an efficient transport system that includes use of low-carbon vehicles, use of public transit as opposed to personal cars.

Ruhamya said the government has entered into an agreement with a car maker that is developing electric vehicles, with the aim of introducing them into the local market.

"We need to invest in research and development to enable us come up with clean and affordable technologies," said Ruhamya.

Rob De Jong, head of air quality and mobility unit at UN Environment, challenged African governments to develop programs that promote the use of shared mobility, use of electric vehicles and use of automatic vehicles.

He said UN Environment is helping Rwanda, Kenya and Nigeria to come up with pedestrian pathways along major roads in the cities.