I was in the room w people smoking marijuana there was ac and fans it was only for about 30 min, if i take drug test week later can i fail secondhand?

Not likely: Depending on the cut off level used for the test, it is possible that you may test positive, however, more than likely you should be clean. Drink enough water daily so that your urine is colorless. For good health - Have a diet rich in fresh vegetables, fruits, whole grains, milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. Exercise at least 150 minutes/week and increase the intensity of exercise gradually. Do not use tobacco, alcohol, weed or street drugs in any form. Practice safe sex. Get HPV vaccine.