Socioeconomic inequalities in secondhand smoke exposure before, during and after implementation of Quebec's 2015 'An Act to Bolster Tobacco Control'.

The persistence of socioeconomic inequalities in SHS exposure despite implementation of new tobacco control laws represents an increasingly worrisome public health challenge, particularly among youth. Policymakers should prioritise the reduction of socioeconomic inequalities in SHS exposure and consider the specific needs of socioeconomically disadvantaged populations in the design of future legislation.