Mr. (Formalde)Hyde Revisited
Happy New Year!!!
And what better way to usher in the New Year than by reuniting with our dear, dear friend Dr. Formalde Hyde, who, has you now know, was indeed very present in the past year. So to quickly recap, last time I briefly introduced formaldehyde’s historic and current situation. From its dark precedents as a mutagen to the recent scandal surrounding Johnson& Johnson shampoos. In this post I shall touch upon formaldehyde’s fate in the environment and the ensuing implications for human health.
Now as many of my close friends know, and as you too shall discover, I have a weird penchant for anything having to do with chemistry…. It has always been a weird obsession of mine. Indeed, some of my favourite moments in Cegep involved my organic chemistry manual (which I named) and which currently resides on my bedside table….. Anyway I digress..
I shall now introduce a few environmental chemistry terms, which shall be of great use for further FemmeToxic fact sheets.
First on the docket this week: ENVIRONMENTAL FATE.
Now environmental fate is normally a term used to describe pesticide behaviour in the environment. However, as I mentioned in the first post, formaldehyde is an ingredient in many pesticides and it is heavily regulated Pest Management Regulatory Agency (PMRA), Health Canada, so understanding its environmental fate is of relevance when trying to understand its effects on the human body.
Generally speaking the environmental fate of a give compound describes what happens to a pesticide after it is introduced into the environment, it equally gives indications in regards to exposure for non-target organisms (Health Canada). A non-target organism, is an organism that falls outside the pesticides specificity range; eg. Herbicide Atrazine, target species: herbs, non-target: frogs.
The processes affecting a pesticide’s environmental fate are called TRANSFER PROCESSES.
Of most significance for us in regards to formaldehyde, are; VOLATILIZATION and ABSORPTION (in the ecosystem).
Volatility refers to the rate at which a given chemical compound can change from a solid/liquid phase to a vapor. Highly volatile compounds contribute to air pollution more readily than compounds which are less volatile.
Absorption refers to the uptake of pesticides and other chemicals into surrounding organisms (http://www.agf.gov.bc.ca/pesticides/c_2.htm).
In the ecosystem, two processes affect absorption; BIOACCUMULATION and BIOMAGNIFICATION.
Bioaccumulation refers to how pollutants enter the ecosystem and Biomagnification refers to increases in pollutant concentration while going up the food chain i.e. you have a given concentration of pesticide X in a plant (xy g/ml); a mouse eats the plant and the pesticide concentration goes up to 2xy g/ml. (there’s a bit more to it but we need not go into too much detail).
These two processes are of great significance when dealing with fat-soluble pesticides (pesticides that can be dissolved in fat). These pose a greater threat to organisms (mammals, HUMANS) higher up in the food chain (because remember; their concentration increases (MAGNIFIES) as they climb up the food chain)
OK! I hope I haven’t lost you! I am now going to take these terms and apply them to formaldehyde.
Formaldehyde is a highly volatile compound, ( so in simple terms, formaldehyde particles are easily released into the surrounding atmosphere).
Therefore, the major exposure pathway for formaldehyde is through inhalation. So if you live close field where a formaldehyde related pesticide is frequently sprayed or you work with formaldehyde, the simple act of BREATHING exposes you to the carcinogenic risks of formaldehyde in the long term, and mild nasal and throat irritation in the short term.
Now on to bioaccumulation and biomagnification, as I mentioned earlier, these processes have greater “influence” in fat-soluble compounds.
Formaldehyde is not fat-soluble so its reactivity in mammalian organisms like humans is rather limited. Indeed, formaldehyde is quickly metabolized in the body i.e. it is rapidly discarded along with other biological waste. This means that formaldehyde doesn’t bioaccumulate ( so it doesn’t remain in the food chain for long) and doesn’t biomagnifiy, mean it doesn’t accumulate in fatty tissue within the organism.
Hence, formaldehyde poses greater risk as a localized carcinogen, only affecting tissues it comes in direct contact with.
Formaldehyde has been linked to nasopharyngeal (nose and pharynx part of airway) cancers, sinonasal cancer and lymphohematopoietic cancer. All these findings on the causal linkage between formaldehyde exposure and cancer incidence can be found in the 12th edition of “Report on Carcinogens” published by the EPA in 2011.
So I am going to leave it at that for now, the third and final segment discussing the Brazilian Blowout scandal will be posted in the upcoming weeks.
Until my next rant!