WAEC - Chemistry (2018 - No. 23)
The following factors would contribute to environmental pollution except
production of ammonia
manufacture of cement
photosynthesis
combustion
Explanation
Photosynthesis is the process of food-making in plants, it doesn't have any by-products that pose a threat to the environment. Infact, the plants use our waste product of respiration (Carbon dioxide) and uses it for the photosynthetic process and gives off oxygen as by-product.