cigarette smoking vitamin b12 levels study B12, MTR & MTRR, and Methylation Descriptive statistics of vitamin B12

Some studies suggest a threshold effect, with minimal impairment at lower exposures but measurable declines beyond ~20 joint-years

You should also see your doctor if a cold sore: spreads to your eye is accompanied by a fever doesnt clear within a week or two is surrounded by crusted or oozing skin HSV is most contagious when cold sores are open and unhealed

References Haye, Vanessa

Low-cost air pollution monitors can provide a way to get information about specific pollutants that may be in indoor air

Conversely, they had lower biomarker levels for polycyclic aromatic hydrocarbons and volatile organic compounds than cigarette smokers