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

Re:1200 times safe level?

[Anonymous Coward]

The danger from dioxin is that it is cumulative. The "safe" exposure is what is tabulted to be "not particularly harmful considering consistent exposure over a lifetime." Much like DDT in the environment building up and eventually killing birds by making eggshells too brittle to be hatched, dioxins build up in animal tissues, and accumulate in epic proportions in apex predators (like humans...)

Dioxins are associted with increased risks for a large number of cancers, as well as with reduced fertility, and various sexual birth defects, among other things.

WHO on Dionxin

Re:Screw dioxin

[TubeSteak]

It's the dihydrogen monoxide that's killing us.

Why do you think I only drink distilled grain alcohol?
God willing, we will prevail in peace and freedom from dioxins and in true health through the purity and essence of our natural fluids

Dioxin and fertility

[fieldstone]

I wrote a paper in 9th grade (13 years ago) about the effects of rising dioxin levels on human fertility statistics. If it's indeed true that human male fertility has been falling steadily since the 1930s, dioxins are most likely the reason. Because they are estrogenic and can cross the placenta, they can cause numerous other birth defects as well, including undescended testes, hypogonadism, micropenis, hermaphroditism, other intersex conditions, and gender identity disorders (if a male fetus' brain or body - but not both - develops in a typically female way because of the presence of dioxin). In mice, it produced male mice who would assume the typically female position with other males, and who were infertile.

The continued presence of dioxins in the environment may well lead to the extinction of the human race, not now or even in 50 years, but whenever the concentration in our tissue (which increases with successive generations) is high enough that none of us are fertile anymore. Of course, by then we'll probably be able to create new people via in-vitro or cloning.

let's look at the research

[simula]

I am extremely dubious that your anecdote is truthful. All the current research points to exactly the opposite of what you describe.

The study that provides the clearest counter-example to your anecdote was on mature human males and tested the effects of soy phytoestrogens on their sex hormone levels as well as a few other factors. The result showed no negative effect:

• Effect of a phytoestrogen food supplement on reproductive health in normal males

Because changes in sex hormones have a much greater effect on infants because they are actively developing, there have been even more studies showing that soy forumula has no negative effect to sexual development:

• Soy protein formulas in children: no hormonal effects in long-term feeding.
• Exposure to Soy-Based Formula in Infancy and Endocrinological and Reproductive Outcomes in Young Adulthood
• Safety of Soy-Based Infant Formulas Containing Isoflavones: The Clinical Evidence

Dioxin Toxicity

[WebSorcerer]

I am an analytical chemist and a pioneer in the development of analytical methods to measure dioxins at extremely low levels in a wide variety of environmental and industrial matrices from 1967 through 1994 as an employee of the Dow Chemical Company. I have published many of these seminal studies in peer-reviewed scientific journals. One of these studies was the first to establish that dioxins are formed in natural processes (such as forest fires) which produces a natural background of dioxins (at very low levels) which existed before man evolved from the apes through modern times.

As an expert in this area, I have served on an Expert Advisory Committee formed by the Canadian government to assess the impact of dioxins in that country. I was the only US citizen on the committee. The report of our findings was published by the Canadian government in 1983.

I have presented papers of my work at American Chemical Society meetings, Annual Dioxin Conference Meetings, and sat in on early meetings of toxicologists to discuss methodology and the significance of dioxin levels found in the environment and industrial settings.

I was an informal advisor to Italian government laboratories in Milan and Rome which analyzed for dioxins associated with the Seveso incident, advising them on how to calculate findings from raw data and how to present the data for interpretation by the toxicology community. This was during a time I was training Dow laboratory personnel in Germany to perform dioxin analyses.

I was involved in developing methods for analyzing Agent Orange (used as a defoliant in Vietnam) for the US Government .

With this background, I have developed informed opinions about dioxins and their hazards.

• There are many chlorinated dioxins, but only a few are toxic; the ones with chlorine in the 2,3,7, and 8 positions.
• If an animal is exposed to a wide range of dioxin isomers (such as fly ash from combustion), the body retains and concentrates the toxic isomers in fatty tissues. This implies that there is a receptor which binds the 2,3,7,8-dioxin isomers. This receptor has another purpose, but the dioxin molecule happens to fit.
• The bioconcentration factor in fish is approximately 3000 (the fish end up with 3000 times more dioxin than the water they live in).
• Dioxin acute toxicity (high single doses) is very species dependent. e.g. Mice are more sensitive than rats, and man is on the low end of the sensitivity scale.
• Long term low level exposure produces an increased risk for some kinds of cancers, and affects the immune system.
• All humans have a natural low level of dioxins (generally less than 1 part per trillion).

My dioxin web site

Re:Dioxin Toxicity

[WebSorcerer]

Since man (and every other animal) has had dioxin in their system at very low levels during their evolution, these low levels are natural to the species. However, the ambient levels of dioxin have risen in recent time due to the activities of man, in most part due to combustion processes. No studies that I know of have addressed whether this has had a deleterious effect and if so, to what extent. Common sense, however, tells me that it probably is not a good thing.

To reduce ambient levels would require either curtailing man-made combustion, or treating all man-made combustion products before they are emitted. I don't think this is a possibility in the near future. However, the efforts to curtail global warming are a step in the right direction, IMHO.

Fortunately, plants to not take up dioxins. I was involved in an early study to determine this. We synthesized radiolabeled tetrachlorodioxin for the US Department of Agriculture for use in a study they did on uptake of dioxins in several plants. Since the analytical methods did not exist at that time to chemically determine dioxins at low levels, they could track the radioactivity to find the answer. They found that corn kernels, for example, contained no detectable dioxin. Root plants, however, had dioxin on the surface of the roots which could be washed off. My advice is to thoroughly wash root vegetables before eating.

Since animals bio-concentrate dioxins they are exposed to, limiting certain of these in the diet would be beneficial. Fish live in water which contains dioxins at very low levels. Their bodies trap a portion of them in their fatty tissues raising the level in their bodies about a factor of 3000. This takes time. Fish which are long-lived in general contain higher levels of dioxin. The US government has advisories on certain waterways against eating more than a specified number of fish per month. Also, large game fish likely have higher levels. Plant-eating animals are not exposed to equivalent levels of dioxin.

There have been several incidences of animals being contaminated with dioxins due to contaminated food. One incident mentioned in the comments above was chicken found to be contaminated with dioxin during a routine food analysis supermarket survey by the US government. The source of the contamination was due to the presence of contaminated clay which is put in the food to facilitate its ability to flow easily in the machinery which transfers it (usually via augers) from place to place during the feed's manufacture.

I was involved as a consultant to a Houston law firm in the litigation surrounding this incident. The clay contamination was of natural origin. Clay is made during the deposition of silt in lakes. It is thus stratified and can act as a 'time machine' for determining substances in the water at the time of the deposit by analyzing core samples. The deeper the sample, the older it is, and the time period can be back to prehistoric ages. The pattern of dioxins in the clay, mined from a depth of about 30 feet, was unusual. It did not match any known source.

It was found that a species of algae could manufacture dioxins. The algae were deposited, along with the silt, in a layer 30 feet below the top of the clay deposit. Since the contamination was of natural origin, and the possibility that clay could be contaminated in this way was was unknown, there was no culpable party, and the law suits evaporated. We are fortunate that our government had the foresight to monitor the food we eat for dioxin contamination.

Personally, I do not worry about dioxins in my diet. Man has evolved in the presence of dioxins and can handle the 'normal' exposure encountered in his daily life. What the government study is trying to do is to determine the level of concern for unusual exposure to dioxins. This, in turn, allows them to control the populace's exposure to dangerous levels of dioxins.

I hope this answers your questions.

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