· Minimize exposure to poisons (including carcinogens and respiratory irritants).
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· Minimize risk of external causes of death.
I agree that toxin consumption is not a good thing, but I'd focus on the toxins you are likely to encounter in amounts great enough to make a difference. This might include things that some people consider "food". I often see an excessive concern about substances of questionable toxicity that are encountered in exceedingly small quantity, and I suspect that in a lot of cases, the stress about the "toxin" is worse for you than whatever it is you're worried about. The Internet may be the greatest tool ever for stoking fears about various substances that are very unlikely to hurt you. Watch out for particulates. Be sure you use a quality mask if you are doing anything that creates dust, like sanding, sawing, grinding etc.
IMHO, we don't spend enough time on external causes of death, primarily accidents, suicide, and homicide. There are actions you can take to reduce the odds of dying of each of these, like learning how to drive properly, driving a modern car, no cell phone use while driving, no driving when drunk, high, angry or tired. No stupid high-danger sports, don't hang out in high crime areas, learn situational awareness and how not to be a victim. Don't have any guns in your home; you're far more likely to use a gun on yourself or someone you know than an intruder.
Avoiding excess medical care is good, but you can take that to extremes. Be sure that you know when to go to the doctor or ER. Some smart people have ended up dead because they thought they could treat themselves and didn't seek medical care when they could have been saved.