Causality versus Correlation: Why don’t we just outright say chemicals cause illness?

In the realm of toxic-free and safer consumer products, you might have noticed that when we refer to chemical health risks we tend to use phrases like, “may increase risk of…” or “connected to” rather than simply saying a chemical “causes” an illness.

Why is this? There are two main reasons, which are tightly connected:

1. We don’t want to overstate claims of causality and lose everyone

One problem the non-toxic movement struggles with is keeping people engaged in forward momentum to change things without scaring everyone away with alarmist or extremist sounding claims. To claim that a chemical causes disease without 100% proof or sufficient evidence, we’re embellishing the truth, simplifying the facts, and we risk discrediting everything completely. While there is strong evidence that there are connections between illnesses and toxic chemicals, toxicologists and ecologists working on these issues work hard to present the information truthfully and in keeping with scientific data.

2. We cannot guarantee causality 100% with the majority of chemicals we suspect to be toxic

Why is this? There are a few reasons, but they come down to a lack of clear, concrete data on the isolated and synergisticˆ impacts of chemicals.

Temporal and spatial disparities:

This is a fancy way of saying that time and space put distance between exposure and illness, creating complexities of pinpointing causes. For example, PCBs are found in areas incredibly far away from anywhere they were actually used. Winds and water currents have moved them around the entire globe, and this is true with other chemicals as well. Additionally, exposure to a chemical in the womb may be the cause of developing a cancer later in life. Toxic chemicals move around so unrestricted, it’s hard to keep track of when and where exposure may have happened that resulted in an illness. On a population scale, some of the effects of chronic exposure to toxic chemicals may not be felt for a generation or two. Or different impacts will be felt generations later that might be hard to trace back to the original source. Today, men are facing decreased sperm counts, and many attribute this to generations of exposure to EDCsˆ.

Our entire world is contaminated:

Scientists are finding it difficult to conduct studies properly due to contamination of our environment, often times eliminating the availability for a control. One example of this situation is from the late 1980s, when two scientists were attempting to conduct studies on breast cancer cell growth in the presence of estrogen. They found all of their cell tissues contaminated with a mystery source of estrogen, which was throwing off their tightly controlled cell experiments. Research halted. At a total loss for answers, they even suspected sabotage at one point. Finally, they tracked down the contamination source to the plastic tubes used to store blood. Chemicals from the tubes, which they’d long assumed to be inert, were leaching into the blood and contaminating it with estrogen. On a broader scale, it’s difficult to assess human health impacts from exposure when all of us are polluted to some degree.

There was little testing conducted to begin with:

Thousands of chemicals were introduced to consumer markets without proper testing of each chemical, let alone testing for synergistic impacts. With some chemicals, it’s hard to say which one causes a problem, or if health risks only appear when chemicals are used in certain combinations. We don’t really know because no one bothered to check that carefully.

The impacts of toxic chemicals are often subtle, rather than direct and obvious:

With some toxins, illness caused is simple to identify because it happens quickly and directly. This is the case with extreme exposure to radiation, or acute poisoning from certain heavy metals. Many pesticides used during the 1950s/1960s had clear and often immediate health consequences for humans and the environment. However, many toxic chemicals on the market today change DNA and slowly impair bodily functions, or cause unseen damage to fetuses. Considering how many chemicals we are exposed to, sometimes it can be hard to identify which one might be the culprit.

 

The current evidence against toxic chemicals remains in the area of correlation. One exception is the case of the DES Daughters. DES (diethylstilbestrol), banned in 1971, was a synthetic estrogen drug given to women during the 1940s and 1950s to prevent miscarriages. The effects of DES were realized after doctors in Boston saw a startling increase in young women with an extremely rare form of vaginal cancer. The mothers of these young women had all taken DES while pregnant. Most of the health impacts of DES were not present at birth, but began to appear as the women reached puberty, childbearing age, and mid-life. DES Daughters are twice as likely to develop breast cancer, and face high rates of other ovarian and vaginal cancers, infertility, and reproductive organ deformities.

Possibly, if we can pinpoint extreme exposure cases or track and correlate specific habits and behaviors with chemical exposure, we may find stronger links between health risks and specific chemicals.

 

References:

https://lucian.uchicago.edu/blogs/colloquium/2014/06/03/toxic-talk-breast-cancer-rhetoric-toxicity-and-the-tyranny-of-cheerfulness/
Endocrine Disrupting Compounds and Cancer in Wildlife and Humans (research paper written by me!)
Our Stolen Future by Theo Colborn, Dianne Dumanoski, and John Peterson Myers
Not Just a Pretty Face by Stacy Malkan

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News Spotlight: Phthalates in Mac and Cheese

A couple days ago, The New York Times published a story about phthalates found in boxed mac and cheese. This morning, the NY Times article was one of the front-page pieces in the Seattle Times. This interest is driven by a recent report from the Coalition for Safer Food Processing and Packaging in which a study of 30 cheese products reveal significantly high levels of phthalates. The powdered cheese packs from boxed mac and cheese contained the highest levels, which was four times that of other cheeses tested (like block or shredded).

So, when I read this, I thought I was safe since I buy organic boxed mac and cheese. Nope. Unfortunately, phthalates were found in organic boxes as well. *sigh*

How do these chemicals get into foods?   Phthalates are used in manufacturing and product packaging and leach into food during production and storage. These chemicals are lipophilic (fat liking), so they accumulate in fats, including our own bodies. Fattier foods will have higher concentrations of phthalates.

What are phthalates and why should we be concerned?   Pronounced thal-eights, they are a group of Endocrine Disrupting Chemicals (EDCs)ˆ primarily used to make plastics soft and pliable. They’re also used as solvents in fragrance and found in a variety of other products including adhesives, shampoos, lotions, cosmetics, body washes, nail polish, detergents, hair styling products, and wood finishes.

These chemicals disrupt hormone function and are linked to birth defects in male infants, endocrine cancers, developmental delays, learning disabilities, and behavioral problems. Phthalates pose a significant risk to men because they target testosterone, leading to feminization, lowered sperm counts, and genital defects. The NTPˆ and EPA consider phthalates to be probable human carcinogens. Exposure to EDCs at times of heightened vulnerability during development changes how the body grows, which can have lasting health consequences, such as infertility.

If you asked most scientists about the top 10 or 20 endocrine-disrupting chemicals they worry about, phthalates would be on that list,” Dr. Patisaul said — Quote from the NY Times article

How do you avoid phthalates?   Well, you’ll probably be exposed at some point without knowing it (they’re everywhere), but you can control some routes of exposure. This is especially important for pregnant women, infants, and young children. Here are some ways you can limit exposure:

  • Reduce your consumption of processed foods and eat fresh fruits and vegetables.
  • Consume low-fat dairy products, since phthalates can accumulate in fat.
  • Ditch the plastic: use glass, ceramic, stainless steel, and wood to store food. If you must use plastic, opt for harder polycarbonate ones and don’t use them for anything hot. Additionally, avoid microwaving food in plastic as the heat increases the leaching of chemicals.
  • Avoid synthetic fragrance and check your personal care products for labeled phthalates. They may also be called DEHP or DEP.
  • Look for personal care products labeled “phthalate-free” and choose organic, non-toxic products.
  • Buy products in glass bottles or jars, especially cooking oils or fatty foods like peanut butter.
  • Make mac and cheese from scratch!

On a broader level, what can you do?   Reach out to companies and express your concern over this issue. Or you can join some of the collective action happening:

Safer chemicals, healthy families:
This petition to the Kraft Heinz Company requests they eliminate all sources of phthalates that may contaminate food.

http://org2.salsalabs.com/o/6639/p/dia/action3/common/public/?action_KEY=24285

Toxic-Free Future:
Add your name to a message that will be sent to the Kraft Heinz Company expressing concern over the testing and asking them to eliminate sources of phthalates in all their cheese products.

http://salsa4.salsalabs.com/o/51668/p/dia/action3/common/public/?action_KEY=20996&tag=KraftEmail

Coalition for Safer Food Processing and Packaging:
This is a petition you can sign like the ones above, but it’s from the group that conducted the study of the cheeses.

http://kleanupkraft.org/

 

References:

https://toxtown.nlm.nih.gov/text_version/chemicals.php?id=24
https://www.nytimes.com/2017/07/12/well/eat/the-chemicals-in-your-mac-and-cheese.html
http://www.seattletimes.com/nation-world/whats-in-your-childs-mac-and-cheese-toxic-chemicals-a-new-study-says/
http://www.safecosmetics.org/get-the-facts/chemicals-of-concern/phthalates/

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Minefield of Chemicals: Toxic Fragrance (part 2)

How to avoid fragrance chemicals:

  • Read labels: avoid “fragrance (parfum)” without any detail
  • Look for “fragrance-free” official label
  • Avoid air fresheners and perfumed cleaning products; try natural ways to eliminate odors
  • Choose products that disclose source of fragrance: essential oil blends or botanicals
  • Find trustworthy companies with certifications that backup claims of “no synthetic fragrances”
  • Switch to green cleaning or DIY cleaning

My last fragrance article focused on perfume/cologne, but fragrance chemicals are present in many more consumer products. We are so inundated with fragrance in our society that its prevalence often goes unnoticed. Go to a store like Target or Fred Meyer (subsidiary of Kroger), walk around all the departments, and notice where you find fragranced products. Fragrance is heavily used in personal care products, but it’s also used in clothing, children’s toys, cleaning supplies, trash bags, Kleenex, and even feminine hygiene products.

The heavy use of fragrance is one of the worst problems because it makes everyday life difficult for those with sensitivities, limits consumer choices, and exposes people to toxic chemicals without their consent. The use of fragrance in public space is similar to the secondhand cigarette smoke issue. Smoking and using fragrance are not just individual lifestyle choices because they affect other people without their consent. This also pertains to company choices to use fragrance in public spaces, such as air fresheners in hotels or workspaces. Additionally, individuals should not have to work so hard to find products that are free of fragrance chemicals or are not unnecessarily scented. Even products labeled as “unscented” sometimes contain fragrance to mask the smell of other chemicals. The EPA has defined “fragrance-free” as an official term manufacturers can use to indicate that a product contains no fragrance chemicals; this is part of the Safer Choice label program.

So, what are some of the toxic chemicals used in fragrances and why should we be concerned? In my last fragrance post, I went over briefly some of the health risks associated with fragrance ingredients. Here, we’re going to examine just a few of the chemicals found in fragrance to give you a snapshot of why synthetic fragrances are so concerning. I think an important thing to keep in mind is how unregulated the fragrance industry is, so we’re not just worried about the health risks alone, it’s a combination of these ingredients being potentially toxic and having basically no safeguards to protect us.

  • Acetaldehyde: Affects kidneys, reproductive, nervous, and respiratory systems. Classified by CA Prop 65ˆ as known/suspected carcinogen. IARCˆ (International Agency for Research on Cancer) and the NTPˆ (National Toxicology Program) list it as a possible carcinogen.
  • Butylated hydroxyanisole (BHA): Possible endocrine disruption; also listed as carcinogen by CA Prop 65.
  • Butylated hydroxytoluene (BHT): Stabilizer and preservative. Eye and skin irritant and possible respiratory system irritant. Limited evidence of thyroid damage, including cancer, from BHT.
  • Dichloromethane (methylene chloride): Shown to cause mammary gland tumors and classified as possible carcinogen by IARC and NTP. Also, possible carcinogen to individuals working with it. Use is restricted by European Commissionˆ and it’s been banned by the FDA.
  • Diethyl phthalate: Fragrance solvent that’s a possible endocrine disruptor and neurotoxin; poses threat to reproductive system. Irritates eyes, skin, and respiratory system.
  • Formaldehyde: known human carcinogen. Banned in personal care products in Japan and Sweden. European Union and Canada restrict it. CA Prop 65 states in gas form, its carcinogen. Individuals working with formaldehyde are at risk of cancer and immune system impairment.
  • MEA, DEA, TEA – ethanolamine: When used in conjunction with certain preservatives, they form nitrosamines (a chemical class). The IARC and NTP consider various compounds in this chemical class as possible or known carcinogens.
  • Oxybenzone (BP-3): This UV filter is a possible EDCˆ; it might be toxic to liver cells and can accumulate in the body. European Union regulates its use in cosmetics.
  • Propyl paraben (propyl p-hydroxybenzoate): Possible endocrine disruptor (EDC). Banned by Denmark for children’s products under 3 years old. European Commission restricts its use in cosmetics.
  • Styrene: Toxic to blood cells and liver when ingested; neurotoxic when inhaled. European Commission classifies it as a “category 1” endocrine disruptor, which means there’s strong evidence that it is carcinogenic.
  • 1,4-Dioxane: This is a byproduct of making other chemicals and a common contaminant in final products. Since it’s a contaminant, it doesn’t need to be disclosed on ingredient labels. Under CA Prop 65, it’s known or suspected to cause cancer and birth defects. IARC and NTP both list it as possible carcinogen.

These substances are only a few of the thousands used in fragrance blends, but it gives you a good sense of the types of health concerns we’re dealing with. The evidence to support health risks is weak though, because most substances are not really tested. It’s difficult to make environmental and public health assessment on substances when there is insufficient data.

In addition to these chemicals, there is some evidence that certain chemical compounds found in essential oils may be harmful to our health and the environment. My next post in this fragrance series will dive deeper into that aspect.

 

References:

http://www.womensvoices.org/fragrance-ingredients/report-unpacking-the-fragrance-industry/
http://time.com/3703948/is-perfume-safe/
http://www.ewg.org/sites/default/files/report/SafeCosmetics_FragranceRpt.pdf
http://www.safecosmetics.org/get-the-facts/chemicals-of-concern/fragrance/

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