The short answer to your question is probably yes, there is such a
preservative, but it is not necessarily a risk to those who live
nearby.
Traditionally railroad ties have been preserved in Creosote, and
creosote is suspected of being a carcinogen to humans. If you have
heard anything related to railroad ties leaching toxic chemicals,
those statements were probably referring to creosote.
"A railroad tie … is treated with a preservative, usually creosote, a
distillate by-product of coal tar…. Coal-tar creosote is the most
widely used wood preservative in the United States. However, The
International Agency for Research on Cancer has determined that
creosote is probably carcinogenic to humans and the EPA has declared
it a "restricted use pesticide".
RAILWAY TECHNOLOGY - RAILROAD TIE
http://www.railway-technology.com/contractors/rail/railroad-tie.html
==================
ABOUT CREOSOTE
=================
" Creosote is a complex mixture of many chemicals. About 300 chemicals
have been identified in coal-tar creosote, but there could be 10,000
other chemicals present in the mixture. Three of the classes of
chemicals found in coal-tar creosote that are known to cause harmful
health effects are polycyclic aromatic hydrocarbons (PAHs), phenol,
and cresols…."
" Creosote can enter the body through the lungs as a contaminant of
air, through the stomach and intestines after eating contaminated food
or drinking contaminated water, or through the skin after contact with
treated wood. Many of the components of the creosote mixture, such as
PAHs, are rapidly absorbed through the lungs, stomach and intestines.
… The EPA has determined that cresols are possible human
carcinogens…."
" Creosote is made up of about 75-85 percent PAHs. According to
ATSDR's Toxicological Profile on PAHs, "Studies of people show that
individuals exposed by breathing or skin contact for long periods to
mixtures that contain PAHs and other compounds can also develop
cancer.""
==========================
CREOSOTE AND CANCER
==========================
" The Department of Health and Human Services has determined that
these three PAHs are known animal carcinogens. The EPA and the
International Agency for Research on Cancer (IARC) have determined
they are probable human carcinogens.."
"According to the National Institutes of Health (NIH), in animal
studies, benzo[a]pyrene induced malignant and benign forestomach
tumors, mammary tumors, lung adenomas, skin carcinomas and papillomas,
tracheal papillomas and carcinomas, squamous cell carcinomas of the
lung, lung tumors, tracheobronchial tumors, squamous carcinomas of the
lung, local sarcomas, hepatomas and lung adenomas, abdominal
fibrosarcomas, mammary and uterine carcinomas, mammary carcinomas,
local tumors, and an increased the incidence of lung adenomas and
initiated skin carcinogenesis in the offspring"
All of the above are quoted from the following document, which I found
to be very thorough. You may want to read it through entirely.
BEYOND PESTICIDES - Petition For Suspension and Cancellation of
Creosote
http://www.beyondpesticides.org/WOOD/creosote_petition.htm
=========================
RISK OF EXPOSURE
=========================
The primary at-risk population for creosote exposure is workers in the
wood preserving industry who come into direct contact with high levels
of creosote on a daily basis.
However, your question addresses the risk to people who live near
railroad tracks. The most common exposure to creosote is via direct
skin contact with creosote contaminated soil. Thus, exposure of local
residents to creosote on railroad ties could come via the following
vectors ---
Children – playing around or near tracks and ingesting creosote laden
dirt via unwashed hands.
Children or adults – being exposed via "used" railroad ties (or
utility poles) that many people use for boxed gardens and sometimes
even for home construction.
Children or adults -- breathing vapors from freshly treated railroad
ties
*note that all of the above also apply to utility poles, bridges, and
fence posts
And finally, anyone who drinks ground water that is contaminated by
creosote is at risk. This risk would be dependent on how much creosote
is present and where the water comes from. For example, if you are
dealing with a single set of old train tracks near your house and a
municipal water system, the likelihood of contamination is going to be
low. But, if you are dealing with newly installed, creosote laden
ties, 12 feet from your well, this would present a high risk.
"Drinking water that is taken from groundwater near wood treatment
facilities, utility poles, or hazardous waste sites may also be
contaminated with creosote. This is of particular concern where
drinking water supplies are unregulated, such as in rural areas and
where people have private wells."
BEYOND PESTICIDES - Petition For Suspension and Cancellation of
Creosote
http://www.beyondpesticides.org/WOOD/creosote_petition.htm
If you have a well and have any concern that your well water is
contaminated, you should have it tested.
=====================
ALTERNATIVES
===================
Since the EPA declared creosote "restricted" other non-wood materials
are being used to manufacture railroad ties. For example:
"The Primix tie is made of steel, concrete and a durable long lasting
composite. Polywood manufactures structural plastic lumber from
post-consumer and post-industrial recycled plastics which is then made
into railroad ties."
RAILWAY TECHNOLOGY - RAILROAD TIE
http://www.railway-technology.com/contractors/rail/railroad-tie.html
====================
ADDITIONAL READING
=======================
PUBLIC HEALTH STATEMENT FOR CREOSOTE
http://www.atsdr.cdc.gov/ToxProfiles/phs9009.html
So, again, to answer your question – Yes, most railroad ties are
soaked in a wood preservative, creosote, that *may* cause cancer in
humans.
However your actual risk will be dependent on the amount of exposure
you have to the creosote. If you are not drinking contaminated water,
are not using railroad ties around your vegetable gardens and are not
allowing children to play in contaminated soil, the risk to you and
your family will be low, if any.
I trust that answers your question. If anything I've said isn't clear,
or if any of the links don't work, please feel free to ask for
clarification using your CLARIFY QUESTION button.
Thanks for your question!
-K~
search terms:
railroad tie preservative
creosote railroad tie EPA
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