Only if you don't get more from it via food into your body
The original post I commented on talked about bioaccumulation. Your original post calculated how much was left after certain amounts of time. But now you were suddenly always talking about something else? Please stop moving the goalposts.
Simple math: 1mg * 2^10 (for easy calculation) equals 1 gram. 1gram * 2^10 (now we are at 2^20, which equals 20 years) equals 1kg
Are you assuming that the biological half-life is 1 year? Because it isn't. Which I said earlier. And which year acknowledged in your previous post. It is 70 days. That means that 20 years is roughly 100 half-lifes. So after 20 years, the proportion of the original material that is left is 2^-100, which is approaximately 10^-30. Or roughly 1/(10 millions * Avogardos number). Which means we need top start out with 10 million moles to have 1 atom left after 20 years. 10 million moles of something that weighs around 100 g/mole is a billion grams. Or a million kg. Or a thousand tons. So no, the correct answer is not "far away from multiple tons". Your answer is, but "Your mass is unfortunately way off