Urban farming is attracting in many parts of the world, however, pollutions in urban areas are much more concentrated! and can threaten the products quality. Why governments, despite know this fact, are favoring urban farming?
Government favour urban farming as a means of diversifying the sources of food to combat food insecurity. Urban farming includes rearing chicken and growing crops. In fact for chicken, the urban farmers outshine the rural counterparts. More interesting is the fact that there are more people in urban area.
I can say that it is a safe choice if care is taken by applying best practices of agriculture. It should be encouraged and ban some pollutants like pesticides and other chemicals
Nowadays, farming is very precise and upgraded like, drip and sprinkler irrigation and many other advanced techniques like Hydroponic, etc. so they are very safe and having very little pollution.
Urban farming is very helpful in sustaining the availability of the produced in the urban areas. The government is in favor for it because it is safe. The area is usually covered with screenhouse and the owner of the area follow the standards on proper sanitation for the environment where the farm is located.
https://www.nature.com/articles/531S60a
Perspective: City farming needs monitoring
Meharg, A. A. (2016). Perspective: City farming needs monitoring. Nature, 531(7594), S60-S60.
Urban water pollution and irrigated vegetable farming
in Addis Ababa
Gebre, G., & Van Rooijen, D. J. (2009). Urban water pollution and irrigated vegetable farming in Addis Ababa.
https://www.nature.com/articles/s41598-020-66159-7
Assessing Nutrient Removal in Stormwater Runoff for Urban Farming with Iron filings-based Green Environmental Media
Wen, D., Chang, N. B., & Wanielista, M. P. (2020). Assessing Nutrient Removal in Stormwater Runoff for Urban Farming with Iron filings-based Green Environmental Media. Scientific reports, 10(1), 1-13.
https://www.abajournal.com/magazine/article/plowing_over_can_urban_farming_save_detroit_and_other_declining_cities_will
Plowing Over: Can Urban Farming Save Detroit and Other Declining Cities? Will the Law Allow It?
Choo, K. (2011). Plowing Over: Can Urban Farming Save Detroit and Other Declining Cities-Will the Law Allow It. ABAJ, 97, 43.
https://scholar.google.fr/scholar?hl=fr&as_sdt=0%2C10&q=urban+farming+and+urban+pollution&btnG=
Urban Farming - A Sustainable Smart Farming Approach
Sasmitha, R., Pandiyan, M., Sivaji, M., Suganyadevi, M., Thilagavathi, T., & Yuvaraj, M. (2020). Urban Farming-A Sustainable Smart Farming Approach. Biotica Research Today, 2(5 Spl.), 323-324.
A recent study determined that, even though urban soil can have higher levels of lead, the “benefits associated with urban agriculture far outweigh any risks.” Specifically, though the soil itself may be harmful, that doesn't translate to the food grown in the ... https://www.foodandwine.com/news/urban-farming-safe?amp=true
Urban agriculture can help solve a host of urban environmental problems, from increasing vegetation cover (thus contributing to a decrease in the urban heat island intensity), improving the livability of cities, and providing enhanced food security to more than half of Earth's population. https://www.teensforfoodjustice.org/why-urban-farming-is-key-in-the-fight-against-hunger-and-climate-change/
The beauty of urban farming is that it not only produces an abundance of organic, locally grown food, but also has a social, economic and communal impact. Urban farming has the potential to become a global green evolution, improving the economy, sustainability and health of our urban communities. https://www.smartcitiesdive.com/ex/sustainablecitiescollective/impact-urban-farming-new-york-city/81916/
The disadvantages associated with urban agriculture
The potential for disease transmission if proper food and environmental safety precautions are not in place.
Exposure to pesticides and herbicides.
Contamination from animal waste.
Urban soils may be contaminated and unsuitable for food production.
Etc.
https://ecosystemsunited.com/2018/12/18/the-disadvantages-associated-with-urban-agriculture/amp/
I agree with Chinaza Godswill Awuchi . The links shared by him are very useful, especially the third one.