Respuesta :

the mental faculties (judgement) with Alcohol levels as low as .02% 
I believe the answer is: the mental faculties (judgement) 

Alcohol would impaired the part of our brain that would restraint our behaviour when we perceive those behaviours as 'risky'. This make us become much more likely to do things such as speeding, fighting, or going home with strangers.
The mental faculties (judgement) could be affected with around 0.02% concentration of alcohol.