Your Health and Rail-tie Processing in Williams Lake. Part 2: Rail tie chipping

NAME THIS PARK

Did you know that the area immediately behind the rail cars shown here, piled high with chipped rail-ties, is zoned by the City of Williams Lake as Park? Does anyone want to suggest a name the city might adopt for this park?

Exactly how long this area has been used for the storage and chipping of creosote treated rail-ties is unclear. Even city managers do not seem certain. It is believed that the storage of chipped rail-ties began in 1995 (the same year it was zoned as Park) and that the on-site chipping began in the early 2000s. This is concerning.

These rail-ties are being chipped for the purpose of supplying fuel to Capital Power (formerly EPCOR) in Williams Lake. In a study performed in 2001, Lanfranco and Associates reported the following pollutant concentrations in the rail-ties used in Williams Lake (warning- tedious numbers immediately ahead):

1) Dioxins/furans 4,040 pg TEQ /gr (compare to 1 pg TEQ /gr for normal wood waste);

2 )Polycyclic Aromatic Hydrocarbons (PAHs) 7,361,000 ng/gr (compare to 12,353 ng/gr for normal wood waste)

3) Chlorophenols 72,093 ng/gr (compare to 30.0 ng/gr for normal wood waste).

The area being used for chipping and storage is at the end of what most people in Williams Lake consider the city's main street, Oliver. It is immediately above the river valley, literally piled to the edge, where rain runoff can rapidly transport pollutants downhill. No one I asked seemed to know just what volume of chipped rail-ties are being stored here but all of the available land appears to be filled with chips stacked higher than the top of the semi-trailer truck seen in this photo.

Unchipped creosote treated wood has been shown to leach dioxins into nearby water (Wan 1995). Chipped ties are more concerning because:

1) The surface area of the chipped ties is vastly greater than that of the unchipped ties and rain water or melting snow running across this area would be expected to carry away much more of the pollutants of concern;

2) The chipping produces dust which:

a) has an even greater surface area to leach pollutants into the soil;

b) can be transported by wind, spreading pollutants into a larger area and increasing risk of human exposure by inhalation and contact;

3) The large surface area increases the amount that will evaporate into the air on hot days, creating odour problems in the commercial core of the city.

This activity is being carried out downtown. It is true that this area has been used as a railroad service yard since around 1919, and it is likely the soil is already contaminated. The current use, however, would reasonably be expected to leach quantities of toxic materials into the surrounding landscape at a scale that has not occurred previously. These toxins are considered some of the most serious with respect to human health.

This is because....

Dioxins. Dioxins were the contaminant in Agent Orange that led to serious health impacts during the Vietnam War. They are both cancer causing and acutely toxic to almost every human organ system (e.g., immune, skin, liver, muscular etc.). Exposure to 70 micrograms per kilogram body weight is enough to cause a Rhesus monkey to rapidly lose weight and its hair and fingernails (IARC 1997). The amount of time it takes the body to naturally rid itself of dioxins, assuming no additional exposures, is measured in many years and they last even longer in the environment. People should not be exposed to dioxin sources. The Canadian Environmental Protection Act desires that they be 'virtually' eliminated (CCME 2001) but large quantities are currently being processed in downtown Williams Lake.

Polycyclic Aromatic Hydrocarbons (PAHs). My Masters degree was focused on the toxicity and metabolism of a particular PAH known as benzo(a)pyrene. It, as with dioxins, is listed as a Group 1 Carcinogen, is known to bioaccumulate (i.e., exposures accumulate in the body and in the food web over time) and is very persistent in the environment. For a sense of how long, consider my story relating to the Exxon Valdez oil spill. The creosote in rail-ties, as it is a coal tar, is mostly PAH in content.

Chlorophenols. These are suspected carcinogens (Group 2A) but more significant as acute toxins. Exposure has been shown to cause skin and liver damage, as well as low birth weight. For general information on chlorophenols, follow this link to the US Department of Health and Human Services.

This material should not be produced or stored within an urban area. If some of the information above sounds concerning, consider what would happen if the stored chips caught fire. That will be the focus of my posting tomorrow.

References

[CCME] Canadian Council of Ministers of the Environment. 2001. Canada Wide Standards for Dioxins and Furans. 12p. Available from: http://www.ene.gov.on.ca/envision/gp/A7appendix.pdf

[IARC] 1997. See Part 1 for full reference.

Lanfranco and Associates Inc. 2001. TransCanada Power Emissions Survey Report: Regular Woodwaste and Railtie Woodwaste. Prepared for TransCanada Power. Available from the BC Ministry of Environment.

Wan MT. 1995. Treated wood as a source of dioxin/furan releases. Organohalogen Compounds. 24: 109-114.

Hat Tip: Marten Lettinga, Chemistry, Thompson Rivers University, for locating some of the references

Photo: view of the rail-tie chipping area immediately behind the Station House gallery.

Photo Credit: R. Higgins