Wednesday, May 9, 2018

The Low Dose Effect

The dose makes the poison and, basically, anything can kill you in high enough doses.   That is the thought behind most US based federal chemical regulations and general thinking with regards to chemicals.  Even too much water can be lethal- which is why many chemical companies and federal regulators tell you that you should not worry about small amounts of chemicals in every day items because they are "such small amounts that they can do no harm". The status quo for chemical regulation, thus, is to find 'safe' levels of chemicals ...assume that - because it is under a certain level- you will be safe.   

Research, however, has found two major flaws with this line of thought.

1.  Chemicals Cause Different Effects at Different Levels New research, actually suggests that some chemicals are actually  more dangerous than previously believed at low levels - especially when acting in concert with other chemicals.

Endocrine disrupting chemicals, which can be found in plastics, pesticides, makeup, personal care products, toys, art supplies, etc and who mimic human hormones, seem to act in this such way.  Some of the most common endocrine disrupting chemicals have shown proof that they can cause effects on a human body even at very low doses.  Furthermore, some actually cause completely different effects at low levels than at higher levels.  

 A 2016 study from Tufts University found " health effects "are remarkably common" when people or animals are exposed to low doses of endocrine-disrupting compounds"  The study found serious effects  on every age group studied from fetuses to aging adults – including links to infertility, cardiovascular disease, obesity, cancer and other disorders.

Additionally, some endocrine disrupting chemicals  were found to produce health effects at low doses that did not occur at high doses.  Essentially you can have a chemical not have any effect at high doses and yet a lower dose may trigger a disease (an example of this is the  breast cancer drug tamoxifen.  At high doses it inhibits breast cancer, but at low dose it can actually stimulate breast cancer growth).   

Bottom line- many of the most common chemicals found in everyday products simply have no safe dose levels.   Another great example is lead- there is no safe dose level of lead - a very well known neurotoxin.  


The traditional thought of "low dose = no worries" also fails to take into account the reality that we are all exposed to many different chemicals through many different products every single day (we are talking about hundreds of different chemicals a day).  Thus, many chemicals we are exposed to at low doses seem to  combine with other chemicals  at low doses to produce big effects.  

Chemicals add up inside of us.   Chemicals linger even longer inside our youngest children's bodies (since their body's detoxifying process is often not as mature nor effective as an adults) allowing combinations of similar chemicals to mix together and produce larger effects. 

What Does This Mean for You?

Basically, do what you can to reduce your family's exposure to chemicals- every little bit does count and can be beneficial.   

Currently there seems to be no safe dose level for endocrine disrupting chemicals because our endocrine system is designed to act/be affected by very low level changes. By design, hormones work in the body at a part per billion and even trillion level (comparable to something like a teaspoon in an Olympic sized pool).... so it makes sense that synthetic hormones would do the same.  

Special caution should be taken during different periods of development.   During our 'windows of susceptibility"  (fetal development, pre puberty, puberty, pregnancy and menopause- periods in life when a human is most susceptible to chemicals) we are especially at risk of being affected by endocrine disrupting chemicals  - especially during pregnancy, when tiny shifts in a mother's natural hormone levels  can have  big health effects on the fetus.  Tiny amount of exposure to manmade hormone mimicking chemicals do too.   

What are the most common endocrine disrupting chemicals?

  • phthalates:  chemicals that increase the flexibility of plastic products such as shower curtains and food wrapping.  Phthalates are also used to 'bind' fragrance chemicals to any given product/substance.  Phthalates can be found in:   personal care products, perfume, home fragrance, cleaning products, toys, food containers, food preparation equipment, school supplies, sports equipments etc.
  • To decrease try:   using less plastic (switch to glass or stainless steel when possible), using fragrance free products, purchase food straight from a farmer or, at least, foods that have had the least amount of processing possible.

  • BPA (and similar replacement chemicals) BPA is a chemical used to make transparent plastics hard.  BPA in the US is now illegal in BABY products made for eating (bottles, pacifiers), however the alternative chemicals being used have not been tested for safety, so when a product or even a toy says "BPA free"  you should remain cautious.  BPA is also still common in the lining of cans used for canned foods and  thermal store receipts. BPA is an especially dangerous endocrine disruptor since, even small amounts of this chemical, have been shown to cause serious reproductive damage, especially when the exposure occurs in utero. Exposure may cause prostate cancer, breast cancer, female infertility, and obesity.
  • To decrease try: Refuse thermal store receipts or make sure you wash your hands after handling them.   Eat fresh foods not canned foods.  Throw out clear plastic that has become cloudy due to use and age. Do not buy plastic 'BPA free' products; when possible switch to glass or stainless steel

  • Atrazine: Atrazine is a herbicide and is the pesticide most commonly found in American drinking water. The European Union banned it in 2004, but it is still legal in the US.   Atrazine's primary use is to control weeds in corn crops that cover much of the Midwest... a job the very toxic glyphosate  (found in the popular Roundup) is used for too. ... But because so much Roundup has been used, weeds are growing resistant. More and more farmers are having to now switch to atrazine, a known hormone-disrupting chemical. 
  • To decrease try: Buying organic foods

  • Dioxin:  is a common by-product of many (chlorine containing) chemicals  when these are burned or treated.  Dioxins are given off through production of pesticides, PVC plastic, metal refining.  Even popular cleaning products can give off dioxins.  Dioxins are highly toxic and can cause cancer, reproductive and developmental problems, damage to the immune system, and can interfere with hormones.  Dioxins also stick around in the environment for years and tend to accumulate in fatty tissue of animals- in fact our main form of exposure to dioxin is  through eating fatty fish or meats or dairy products.  
  • Children, nursing infants, some workers, people who eat fish as a main staple of their diet, and people who live near dioxin-release-sites are potential high-exposure groups. Children and fetuses are the most susceptible to the health effects of dioxin exposure.
  • To decrease try: Clean with natural products like vinegar and baking soda.   Avoid fatty foods like fatty meats and dairy

  • Flame Retardant Chemicals:   There are many different types of flame retardant chemicals.  These chemicals are still commonly found in electronics, upholstered furniture, cars, children's car seats and even some crib mattresses have been linked to  cancer, infertility, obesity, lowered IQ and learning problems, and other diseases and disorders. 
  • To decrease try: buying certified organic mattresses.  When purchasing new upholstered furniture read the label and make sure it specifies it does not use chemical flame retardants.  For more on buying flame retardant free car seats click over to our past posts here

  • PCBs:  PCBs are classified by the International Agency for Research on Cancer as known human carcinogens, they are known to accumulate in wildlife and  linked to reduced IQs, cancer, suppressed immune systems and endocrine disrupting.   They are considered so toxic that they were banned in the U.S. in 1979.... unfortunately a new study recently found PCBs, in kitchen cabinetry- apparently an unwanted byproducts of wood sealant breakdown.   Because of this, these banned chemicals are now common in offices and schools and many homes.
  • To decrease try: Choose solid wood cabinetry or at least open windows often to air out internal home (and school and office) air.  Consider investing in an air filter

1 comment :