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Exposure To Motor Lubricants & Solvents

car-engineMuscle car plus motor head does not equal muscle head, although it could. The first pair evokes positive images for those who remember Holley carburetors, dual exhausts, Hurst shifters and four on the floor (gears, that is). The muscle cars of the 60’s were exciting to drive and fun to work on. That was an era when there was enough room in the engine compartment to swing a socket wrench. Of course, without air conditioning there was plenty of space to climb inside and yank a Champion or two. Considering that engine oil is to a car what blood is to the human body, you can bet that oil changes were dutifully timed events. Unlike blood, oil has changed over the years. Modern engine oils have viscosity-index improvers, antioxidants, dispersants, corrosion and foam inhibitors, and anti-wear agents that were absent half a century ago. Also some oil formulations vary from state to state. In the past, wearing oil and grease on hands and clothes was a badge of honor, an announcement that proclaimed mastery over a demanding technology. Today, protective gloves need to be the order of the day.

Mechanics and other auto workers who are exposed to used crankcase oil have experienced skin rashes, blood effects similar to anemia, headaches and tremors. Along with used oil, they are exposed to other chemicals/toxins common to the auto industry, including fluids, metal particles and fumes. Used oil may contain chemical constituents that result from the internal combustion process, such as the polycyclic aromatic hydrocarbons (PAH) associated with benzene and related suspect carcinogenic compounds. Systemic effects of exposure to used oils and automotive fluids may include elevated blood pressure, aberrant red blood cell values (caused by lead exposure), stress to the liver (as indicated by irregularities in enzyme markers), and skin rashes (Clausen and Rastogi, 1977). In mechanics who work with new cars, interior cabin materials present no less a threat to health. Exposures to high concentrations of the aliphatic hydrocarbons that render the appealing “new car smell” are found to accumulate in the body (Yoshida, Jan 2010 and Aug 2010).

What’s the big deal?

There is more than one route to internal toxicity. You can swallow almost anything, inhale too many other things, and absorb more than a handful of the remaining damaging substances available to the environment. Compounds that contain only hydrogen and carbon are called hydrocarbons. The number of atoms of either element can change to make a different substance, one of the simplest being CH4, known as methane. During the refining of petroleum, one kind of hydrocarbon can be converted to another, giving us gasoline, naphtha, kerosene, lubricating oils and more. Adding chlorine to the C-H backbone reduces flammability and increases stability, resulting in chlorinated hydrocarbon solvents that can be used to clean, degrease and thin almost anything. At high temperatures that vary according to the compound, they give off seriously toxic gases and can enter the body through the skin.

Most foreign substances are unable to penetrate skin, the outer layer of which is an effective barrier to most inorganic particles. But damage to the stratum corneum, whether by abrasion, exposure to U-V light, or by chemical insult, can allow penetration. Lubricating oils, some waxes, and greases can induce primary irritations and photosensitivity to skin. The severity depends on the nature of the oil, the integrity of the skin, the frequency and length of contact, and individual susceptibility. Certain size molecules of chlorinated and simpler hydrocarbons, and of those with a greater number of carbon atoms than hydrogens, are more apt to enter skin than others (Riihimaki and Pfaffli, 1978) (Babu et al, 2004).

Among the riskier materials are automotive and industrial solvents made with trichloroethylene or tetrachloroethylene, known to penetrate the skin and suspected of being carcinogenic. Up to the 1970’s, trichloroethylene was used directly on humans as a general anesthetic and as a wound disinfectant. Believe it or not, it was also used as a flavoring agent for coffee. This nonsense was halted in 1977. Today it’s being used as a degreaser, as a cleaner for textiles, as an additive to inks and paints, and as an ingredient in PVC (the polyvinyl chloride in plastic plumbing). At least it won’t catch fire. Strangely, the metabolites of trichloroethylene are identical to those that follow the chlorination of municipal water supplies, namely chloral, chloral hydrate, monochloroacetic acid, and di- and trichloroacetic acids (Simon, 2005).

Tetrachloroethylene is also known as perchloroethylene, most commonly used in dry cleaning.  Exposure, either respiratory or dermal, may cause depression of the CNS, liver and kidney damage, impaired memory and headaches (DHHS, 1991). Like trichloroethylene, it is non-flammable and stable. Earlier in its history it was used in commercial refrigerants and auto air conditioners. But it’s an excellent solvent for organic materials such as the greases and lubricants used in the automotive industry…and it dissolves fats from skin, resulting in skin irritation.

Does It Hurt?

Once in the body, either through the skin or the nose, these hydrocarbons attack the cell membrane and the proteins that prevent entry of toxic compounds. A bodyguard enzyme called ATP-ase directs cell traffic by letting food and energy in, and by escorting wastes and toxins to the door. Another of its jobs is to control the balance of sodium and potassium. Sodium tells a cell to contract so you can pick up a tool, and potassium tells it to relax so you can put it down again. Chlorinated solvents, though, attack the fats from which the membrane is made and cause it to lose its shape and to resemble a half deflated basketball. Now, it can’t do its job and you get tired quickly and your thinking becomes foggy. Once ATP-ase gets dissolved by chlorinated hydrocarbons, any work that requires muscle power becomes more and more difficult. There are no alternatives to crankcase oil, but there are optional solvents and degreasers. Read the labels, wear gloves, and protect your eyes. No matter how thick-skinned we think we are, we really aren’t.

References

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Babu RJ, Chatterjee A, Ahaghotu E, Singh M.
Percutaneous absorption and skin irritation upon low-level prolonged dermal exposure to nonane, dodecane and tetradecane in hairless rats.
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Clausen J, Rastogi S.
Heavy metal pollution among autoworkers:I Lead.
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Clayton GD, Clayton FE, eds. 1981.
Patty’s industrial hygiene and toxicology. Volume 2B: Toxicology. 3rd ed.
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Mutagenic activity and polycyclic aromatic hydrocarbon levels in urine of humans exposed to therapeutic coal tar. Carcinogenesis. 1986; 7:819-823.


DHHS 1991.  (NIOSH) Publication Number 97-155
Control of Exposure to Perchloroethylene in Commercial Dry Cleaning
http://www.cdc.gov/niosh/docs/hazardcontrol/hc17.html


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Edelfors S, Ravn-Jonsen A.
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Filon FL, Boeniger M, Maina G, Adami G, Spinelli P, Damian A.
Skin absorption of inorganic lead (PbO) and the effect of skin cleansers.
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Jorgensen PL, Hakansson KO, Karlish SJ.
Structure and mechanism of Na,K-ATPase: functional sites and their interactions.
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Korpela M, Tähti H.
Effects of industrial organic solvents on human erythrocyte membrane adenosine triphosphatase activities in vitro.
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Francis J. Koschier
Toxicity of Middle Distillates from Dermal Exposure
Drug and Chemical Toxicology. 1999, Vol. 22, No. 1 , Pages 155-164


McDougal JN, Pollard DL, Weisman W, Garrett CM, Miller TE.
Assessment of skin absorption and penetration of JP-8 jet fuel and its components.
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Monteiro-Riviere NA, Inman AO, Riviere JE.
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Naskali L, Oksanen H, Tähti H.
Astrocytes as targets for CNS effects of organic solvents in vitro.
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E Reese and R D Kimbrough
Acute toxicity of gasoline and some additives.
Environ Health Perspect. 1993 December; 101(Suppl 6): 115–131.


Riihimäki V, Pfäffli P.
Percutaneous absorption of solvent vapors in man.
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Skou JC, Esmann M.
The Na,K-ATPase.
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Suzanne E. Simon
Editor’s perspective: The prevalence of trichloroethylene metabolites in public drinking-water supplies
Remediation Journal. Summer 2005; 15(3): 1-4


Vaalavirta L, Tähti H.
Astrocyte membrane Na+, K(+)-ATPase and Mg(2+)-ATPase as targets of organic solvent impact.
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Vaalavirta L, Tähti H.
Effects of selected organic solvents on the astrocyte membrane ATPase in vitro.
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Yoshida T.
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Yoshida T.
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*These statements have not been evaluated by the FDA.
These products are not intended to treat, diagnose, cure, or prevent any disease.

Photosensitivity and Supplements

sun-burnAh, the red, painful skin that feels hot to the touch. Many of us have had the pleasure…or, rather, the pain. In our youth we were not told of what was to come from repeated aspirations to the beauty of the bronze. And, if we were told, we didn’t listen. If you’re a fair-haired beauty, you’re more likely to burn than your darker peers. Skin types range from very light to very dark, but you already knew that. What you may not know is that the sun’s rays penetrate all skin types and wreak havoc on your DNA. Yes, dark brown and black skin tans and burns, though burning is not so common. Ultra-violet damage can lead to serious problems, not only with your skin, but also with your eyes.

There should be a familiarity with the name, “Mayo Clinic.”  Its philosophy of putting the patient first is amply demonstrated in the high percentages of positive outcomes.  When Mayo speaks, people listen.  If you’ve had sunburn, you know the symptoms.  In a recent article by Mayo staff, the Clinic admonishes to, “See your doctor if you notice a new skin growth, a bothersome change in your skin, a change in the appearance or texture of a mole, or a sore that doesn’t heal.”  (http://www.mayoclinic.com/health/sunburn/DS00964).  But the Clinic adds that, “The sun can also burn your eyes.  UV light damages the retina…” and can also damage the lens, leading to “…progressive clouding of the lens (cataracts).”

If you’ve taken all the precautions and still get burned, there must be another reason.  Let’s see, hmmm, you’ve avoided the sun between 10 AM and 4 PM, when it’s the strongest, right?  You’ve been careful to cover up.  Not, if you’re looking for a tan.  You’ve slathered on gobs of sunscreen, too, eh?   Of course, you did don the shades.  How else to look cool, right?

There are alternative ways to combat the results of too much time in the sun, whose tanning effects will last for a few hours after exposure.  While it is safest to spend only twenty, or so, minutes at a time in the sun for the first few days of your vacation, that caveat is ignored.  There may be a saving grace in the judicious use of foods and supplements that provide beta-carotene, the precursor to vitamin A.  A German study published in 2006 states that, “Beta-carotene is a major constituent of commercially available products administered for systemic photoprotection.”  (Stahl. 2006) This piece goes on to say that beta-carotene needs to be taken at doses of almost 50,000 IU a day for about three months before such an effect becomes evident.  That’s about 30 milligrams.  There is no current tolerable upper limit for beta-carotene as there is for vitamin A, which is 10,000 IU for adults.  In an earlier study by the same research group, it was noted that, “Carotenoids are efficient in photoprotection…”  (Sies and Stahl. 2004)  Here, a decreased sensitivity against ultra-violet-induced erythema (redness) was noted.

The carotenoids lutein and zeaxanthin, found in green leafy vegetables and in supplements, are photoprotective for the eyes, where they are present in the retina and absorb blue light, thereby “protecting the underlying photoreceptor cell layer from light damage, possibly initiated by the formation of reactive oxygen species during a photosensitized reaction.”  (Krinsky. 2003)  The addition of green tea to our armamentarium helps protect skin against UV radiation and, for women especially, improves overall skin quality.  (Heinrich. 2011)  If tea is not your “cup,” you might give a go to chocolate.  UV-induced redness is inhibited and blood flow to the skin enhanced by cocoa flavonols.  (Heinrich. 2006)

But what about the PABA?  Topically, used before exposure to the sun, it absorbs ultra-violet radiation, and it will last through heavy perspiration (but not after going into the water).  It even is alleged to soothe the burn after the fact.  Orally, PABA has not shown sufficient photoprotective activity in organized studies to be recommended for everybody, but it might work for you.  However, too much PABA can backfire and cause more problems than it’s worth because it’ll stop the burn but not the alterations to DNA.  It seems to have fallen out of favor.  (Knowland. 1993)

How about the other side of the coin, the one where a supplement can cause photosensitivity?  St. John’s Wort, an herbal used to treat mild depression, may induce light / sun sensitivity, so sun avoidance is suggested—strongly.  There is no evidence to blame other supplements for photosensitive reactions.