Infants Ingest 77 Times the Safe Level of Dioxin

An anonymous reader writes "The Environmental Protection Agency is holding public hearings beginning today to review a proposed safe exposure limit for dioxin, a known carcinogen and endocrine disruptor produced as a common industrial byproduct. It's all but impossible to avoid exposure to dioxin. Women exposed to it pass it on to fetuses in the womb, and both breast milk and formula have been shown to contain the stuff. Research done by the Environmental Working Group has shown that a nursing infant ingests an amount 77 times higher than what the EPA has proposed as safe exposure. Adults are exposed to 1,200 times more dioxin than the EPA suggests is safe, mostly through eating meat, dairy, and shellfish."

Comments

1200 times safe level?

[LordKronos]

It seems to me that if adults typically are exposed to 1200 times what is considered a safe level, then either every adult should be seriously ill from exposure, or the EPA standard for what is a safe level is a bit unreasonable.

Re:1200 times safe level?

[jd]

Not necessarily. It depends on how "safe" is defined. If "unsafe" means that you can expect a statistically measurable drop in life expectancy and measurable increase in related illnesses over a lifetime of exposure (ie: pretty much the same case as you have for smoking-related illnesses), then you would not necessarily have an obviously sick population even though said population was, indeed, sick - merely not sick enough for it to be visible at that time.

Lifetime exposure is one factor. Yearly exposure and daily exposure are other measures. I don't know exactly which of these the 1200x refers to. It matters. It matters a lot. You can't simply assume that exposure is utterly uniform and devoid of any fluctuation, nor can you assume that accumulation is also uniform and devoid of any fluctuation. Thus, the 1200x may well be an average that never actually happens, but where you are very likely to get millions of times safe levels for brief periods of times at intervals in your life. Or it might be that 1200x is the maximum value that the fluctuations are likely to reach, or it might be the root-mean-square value of the fluctuating values, or any number of other things. The summary is useless (as usual) in understanding what the numbers mean.

Or maybe 1200x is not actually the exposure level at all, but rather the peak value observed for bodily accumulation of the toxin. Or the average. Or the root-mean-square. Or some other statistical value.

Regardless, the EPA is usually wildly optimistic - the EU generally permits levels only half the EPA estimates of what is safe, and the value is generally much closer to the value considered sensible by environmental chemists and inorganic biochemists. Both the EPA and EU values are usually also much lower than the values industry will stomach, with the result that either the law is widely flouted (since jobs = votes and nobody is stupid enough to vote themselves out of office by risking jobs through environmental crackdowns) or the law is widely bypassed by moving the most polluting component(s) to places like Bhopal, where the people are too poor or too dead to complain.

(I don't know what the solution is, but since a company pays for whatever it wastes, it would seem to follow that the less you waste the more you make.)

Re:1200 times safe level?

[grcumb]

That said, I agree that the "1200 times safe levels" quote is fear-mongering. Humans are notoriously bad at judging relative risk (see the Bad Science blog for more).

From the WHO site:

• Dioxins are a group of chemically-related compounds that are persistent environmental pollutants.
• Dioxins are found throughout the world in the environment and they accumulate in the food chain, mainly in the fatty tissue of animals.
• More than 90% of human exposure is through food, mainly meat and dairy products, fish and shellfish. Many national authorities have programmes in place to monitor the food supply.
• Dioxins are highly toxic and can cause reproductive and developmental problems, damage the immune system, interfere with hormones and also cause cancer.
• Due to the omnipresence of dioxins, all people have background exposure, which is not expected to affect human health. However, due to the highly toxic potential of this class of compounds, efforts need to be undertaken to reduce current background exposure.
• Prevention or reduction of human exposure is best done via source-directed measures, i.e. strict control of industrial processes to reduce formation of dioxins as much as possible.

In short, dioxins' real danger is not increased cancer risk in the population that ingests it directly. It's the mutagenic risk to our offspring. In layman's terms, you're not going to die of cancer, but your child might be born with a genetic defect that affects their ability to thrive - or maybe even to survive.

A 'safe' dose is therefore difficult to quantify, because we won't know for sure what the impact will be after (for example) 3 generations of exposure at a given level. More to the point, we don't want to find out by waiting to see if our predictions were right. In cases like this, the precautionary principle is by far the better choice.

That's difficult to apply, however, because dioxins are persistent chemicals; they accumulate in the food chain and don't disperse easily. Arguably, there is no such thing as a 'safe' level, because with the passage of time even small annual increments become very large numbers.

As with climate change, decisions deriving from the scientific findings will be largely informed by the moral/ethical/philosophical stance of the policy-makers. The same data set looks very different if you're looking at the problem in terms of the next electoral cycle, as opposed to the next generation.

Re:Kind of makes you wonder...

[Anonymous Coward]

"Nine animal studies conducted between 1973 and 2008 show that dioxin is harmful at levels even lower than in the human studies on which EPA based its proposal. Those human studies, conducted in 2008, explored the toxic legacy of a 1976 chemical plant explosion in Seveso, Italy, which exposed thousands of people to dioxin in unprecedented intensity and left large quantities of the chemical in the soil." source: http://www.ewg.org/dioxin/home

of course ... those studies could have all been flawed ... but ... it's a much more likely possibility that the cancer all the people you know that have cancer comes from something related to their lifetime of high exposures to environmental pollutants.

EWR's press release

[Anonymous Coward]

here's the EWR's press release http://www.ewg.org/dioxin/press

Environmental Working Group's dioxin timeline, complete with citations http://www.ewg.org/dioxin/timeline

I'm a vegan, politcally I'm a progressive (let the flaming begin), and even I was disgusted with the "article" linked in TFS. Piss poor choice dudes, as you easily could have linked to the EWR's press release and allowed the discussion to go from there. But instead we start with a shit "article" from an alarmist site, which stokes an immediate onslaught of comments that outright dismiss even a _possibility_ that dioxin is harmful to humans.

In my 12 years of hanging around here, I sure do miss the days when we'd have a discussion based on the SCIENCE of whether or not dioxin is worthy of our concern

Re:Kind of makes you wonder...

[Cedric Tsui]

I don't think so.
This is a common problem in terms of safety standards. Toxicity of a substance is very hard to quantify. It's easy to take a group of lab rats and see what dosage kills half of them. But what does that say about how tiny amounts of the substance will affect your lifetime chance of developing cancer? Usually, you cant say anything!

If it can't be quantified, then you assume the worst case scenario. I know that when it comes to radiation, we call this the 'linear, no threshold' (LNT) model. If x amount will bring you 50% of the way to death, then x/500 will bring you 0.1% of the way to death. There is no safety threshold, which means that we assume that any ingested amount no matter how small does damage.

Now, the LNT model is pretty much never correct. At least, I've never seen an example where it has held. One example: Swallowing two pounds of vitamin C should kill me based on the LD50 for rats. If we were to apply the LNT model, we'd conclude that vitamin C is toxic and I shouldn't ingest any if I can help it. It's this kind of reasoning why lexan bottles are no longer covering the shelves. Some scientist measured 6-20 parts per billion of BPA in the water contained in one of these bottles.

Does that mean the EPA is unreasonably over protective? Yes. Do I want them to change? ABSOLUTELY NOT! In this case, as in the case for radiation, and for BPA, pseudo estrogen, mercury, etc.., is that we can not prove that exposure to these quantities is safe, and we have reason to believe that they are not. They do not need to be proven dangerous to be banned. They need to be proven safe to NOT be banned.

Re:so.....

[Man On Pink Corner]

Except, here in the US (which is where babies are ingesting 1200 times the safe level of dioxin) we don't live as long as many other developed countries.

You can't make this statement without comparing infant/early-childhood mortality rates, as well as the different policies governments use to determine what a "live birth" actually means. Average lifespan is one of those statistics that becomes fuzzier and fuzzier the more you look at it.

Re:Great

[fuzzyfuzzyfungus]

The safe exposure limit has two major uses:

One, it directly informs industrial hygiene standards for workers exposed to it on the job. OSHA recommendations/requirements will(possibly some decades after the fact, The Business of America is Business(tm) after all) reflect the levels of exposure that are permissible, given the expected health effects.

Two, it informs environmental regulations related to the discharge of the chemicals in question. Dioxins are only "unavoidable" today because their release has historically been alarmingly close to unregulated, and they are fairly persistent little critters. If the safe exposure limit is revised downward, acceptable release limits will(again, possibly with substantial lag, nobody wants to make the American Chemistry Council cry) will be revised downward, so that, as the compounds eventually are degraded or encapsulated, exposures will fall.

Re:so.....

[AlamedaStone]

Oh wow, you dug up exactly one statistic where the US is worse than a lot of countries.

Hey I have an idea... why don't you harp on that single number while ignoring how we are near the top on pretty much every other health metric. That's a winner.

You mean like cost?

Re:so.....

[darthdavid]

This is why I fucking hate economists. PROTIP: Just because something is economically justified doesn't make it the right thing to do. Further, we only have the one planet and just because you'd be happy to live on a brown, smoggy barren dirtball where everyone dies of cancer at 50 doesn't mean everyone else wants to.

Even arguing from a strictly utilitarian point of view (IE yeah they'll live in a polluted shit-hole but atleast they'll be clawing their way up the economic ladder and so should experience a net gain in their standard of living) that argument completely ignores the possibility of developing clean, efficient alternatives and imposing much stricter standards wrt waste disposal where no such alternatives exist and using that clean industry to haul people out of poverty without fucking over the planet in the process.