However, in most countries effluent charges are set at very low levels (in relation to abatement costs), and their effectiveness in influencing the polluters' choice of pollution levels is very limited.
(effluent charges; are set; at very low levels; L:in most countries) (their effectiveness in influencing the polluters' choice of pollution levels; is; very limited)
effluent charges their effectiveness in influencing the polluters' choice of pollution levels
are set is
at very low levels L:in most countries
very limited