Wood preservation facilities, creosote: chapter D-10

10. Environmental and Workplace Monitoring

10.1 Baseline Environmental Evaluation

A comprehensive perspective on the sources and distribution of Polycyclic Aromatic Hydrocarbon (PAH)s in the Great Lakes is provided in the 1983 report of the International Joint Commission’s Aquatic Ecosystem Objectives Committee (11). The report indicates that the major anthropogenic sources of PAHs in the environment are fuel combustion (coal, oil and wood burning), refuse combustion and coke production. Fossil fuels such as crude or bunker oil contain PAHs, and accidental spills from boating and shipping activities contribute considerably to PAH contamination in coastal waters. Levels of PAHs in waters, air and sediments in the vicinity of populated and industrial areas are frequently significantly higher than in non-populated areas. To illustrate PAH levels in the environment, the following lists concentrations found in sediments, water and biota of the Great Lakes.

Benzo(a)pyrene in water is found in the Great Lakes water system at a concentration of 0.012 µg/L and Phenanthrene is found at a concentration of 0.024 µg/L (mean basis).

The sediment data show the influence of anthropogenic sources on PAH levels in the environment (e.g. for Benzo(a)pyrene Lake Superior 0.028 µg/kg versus Lake Erie 0.255 ± 0.152 µg/kg).

The Fish data also show the influence of anthropogenic sources on PAH levels in the environment (e.g. for Benzo(a)pyrene Lake Erie 0.046 ± 0.041 µg/kg and Lake Ontario 0.069 ± 0.044 µg/kg)

Since PAHs are also produced during forest fires and volcanic eruptions (11), they can be considered natural compounds. It has been estimated that forest fires contributed 10% of total PAH emissions in the United States during the mid-1970s (32).

Releases from creosote wood preservation facilities have been reported and are primarily ascribed to historical events resulting from poor operating practices. Contamination of several Canadian preservation plant sites has been reported (33). The available evidence, which is limited and not very conclusive, indicates that the quantities of PAHs entering the environment from treated wood in service are small (34).

The facility should have in hand the background levels of the preservative constituents in the natural environment prior to plant operation. Older mills may not have this information available. A comparative site from a nearby property can be used as a reference. The facility may use the template provided in Table 24 from Chapter A.

10.2 Environmental Monitoring

A possibility of creosote-contaminated ground and runoff from treated wood storage areas must be acknowledged. PAH are persistent and bioaccumulative in the environment and close monitoring studies (such as surface water discharges, groundwater and soil contamination) are recommended to detect and properly assess the degree of such potential toxic releases.

10.3 Workplace Exposure Monitoring

Workplace monitoring generally falls under provincial jurisdiction. Worker health programs should be developed with provincial and/or local regulatory agencies in consultation with a provincial workers’ compensation board and/or department of labour and/or industrial physician/industrial hygienist.

The appropriate components of a site and worker exposure monitoring program are contained in Section 10.2 of Part I, Chapter A - General Recommendations for All Wood Preservatives: Table 25 - Recommended Routine Environmental Monitoring and Table 26 - Recommended Routine Workplace Monitoring.