Concentration of fluorine that cause a phototoxicological effect on the plant is ___________
(a) 0.1μg/m^3
(b) 0.3μg/m^3
(c) 0.5μg/m^3
(d) 1μg/m^3
I had been asked this question during an interview.
The query is from Effects of Air Pollution, Design of Stack Height topic in portion Air Pollution of Environmental Engineering