7 ms·
I don't have access to the paper, but just reading the abstract it gives these numbers: > Exposure modeling results suggested that the highest estimated daily
by DangerousPie 3y ago
I don't have access to the paper, but just reading the abstract it gives these numbers:
> Exposure modeling results suggested that the highest estimated daily intake was 20.3 ng/kg·day for infants drinking microwaved water and 22.1 ng/kg·day for toddlers consuming microwaved dairy products from polypropylene containers.
> Furthermore, an in vitro study conducted to assess the cell viability showed that the extracted microplastics and nanoplastics released from the plastic container can cause the death of 76.70 and 77.18% of human embryonic kidney cells (HEK293T) at 1000 μg/mL concentration after exposure of 48 and 72 h, respectively.
If I'm reading this right, they exposed these HEK293T kidney cells to far higher concentrations (1000 μg is 1000000 ng, and that's per mL) than toddlers would be exposed to from these containers. So the fact that the cells die doesn't really mean much, since exposure to too much of anything will cause cells to die.
The real question is whether the exposure you'd receive from occasional microwaving would be enough to ever cause any meaningful health problems. Unfortunately papers like these always like to talk about dramatic metrics like 'billions of nanoplastics' without putting that into any meaningful context.
- WithinReason 3y agoSo it seems that a concentration of microplastics that's 50 million times higher than a toddler would get still leaves 20% of cells alive? To me this implies that normal exposure levels to microplastics are likely completely harmless.
- Dalewyn 3y agoI wouldn't frame it as "harmless", but it is probably accurate to say any harm is insignificant at worst.
- nucleardog 3y agoIf it's a single, acute exposure sure. I'm no doctor or microbiologist or anything, but there definitely seems to be a strong connection between "things that cause cellular damage" and "increased risk of cancer with long term exposure".
- sfn42 3y agoYeah but cellular damage in the body is not the same as cellular damage in a petri dish. I bet water kills cells in a petri dish. It's just a really useless test to do, that at absolute best gives a vague hint at something that may be true. It's not useful to talk about in any capacity other than "let's explore this further with better experiments".
- cowl 3y agoWe don't know if it can be a long term exposure. We don't know at what rate they are expelled from a live person. And One thing is for sure. Cell Death that this experiment showed off at the unreasonbly hight concentration is still quite the opposite of Cancer. Cancer is Uncontrolled cell multiplication not death. So according to this we could use nanaplastics to kill cancer. See How easy it is to draw any conclussion that you want if you forget to factor the real conditions?
- peteradio 3y agoSleeping next to abandoned nuclear batteries will give you radiation burns and kill you in a few weeks to months, exposure to high radon will give you cancer in decades. Unrealistically high dosages can hint at problems that might occur at low levels.
- sfn42 3y agoDrinking a shitload of water can kill you, not drinking water will certainly kill you. In fact having a shitload of just about anything is likely to harm or kill you. Unrealistically high doses imply absolutely nothing about lower doses.
- pseudosaid 3y agoRead better please
- john-radio 3y agoThis comment is unhelpful; the person you're replying to clearly is not claiming that "absolutely everything that's harmful in large doses is harmful in small doses." > Unrealistically high doses imply absolutely nothing about lower doses. The example they give of nuclear radiation is a clear illustration of how a useful hint can be drawn from the high-level example of harm, a pattern which microplastics might very well follow.
- s1artibartfast 3y agoModels can breakdown at huge scales because they introduce other non-representative factors or nonlinear responses. Sending an astronaut to the center of the Sun and concluding their death is from radiation would be a pretty bad model. Hitting a person with a car would be a pretty bad model for a fly landing on them. The first model is bad because the sun is doing more than just exposing them to radiation. The second model is bad because there's a nonlinear response to force applied to a human body.
- 3y ago
- polishdude20 3y agoThese studies also don't take into account the fact that humans have an immune system that helps protect and repair against cell damage.
- amluto 3y agoThe concentration they used was 1000ppm or about 0.1%. Many things are toxic at that concentration. (This doesn’t cross the threshold of absurdity of “sodium chloride is toxic at that concentration,” but it would be preferable not to drink 0.1% salt water.)
- parentheses 3y agoI agree with your question: > whether the exposure you'd receive from occasional microwaving would be enough to ever cause any meaningful health problems Another question worth asking: How much of the ~20 ng/kg/day makes its way to the kidney cells? Said another way, if one were to consume a liquid concoction with a certain concentration of nano/micro-plastics, what would the total negative effect be? How much would simply be excreted? That answer for babies vs adults may also vary.