ACRD on Twitter

Burning Wet, Salty Hog


On the West Coast of BC, logs are transported and stored in the ocean. Chlorine from the salt water is taken up in the bark, which is stripped form the logs and ground to produce "salty hog." The salty hog is burned in power boiler #4 to produce 60-80 % of the steam required for paper manufacture. Dioxins and furans are created when the salty hog is burned. (Elements such as cadmium are also a concern. Cadmium is toxic in parts per trillion and is present in the tree bark hog fuel.)

Wet, salty hog became a fuel for Catalyst Port Alberni in 1997 when the supply of good quality hog from sawmills disappeared due to the sudden collapse of the Japanese lumber market.

The term "dioxin" (or "dioxins") is a very loose one, referring to a family of complex but related chlorinated compounds with similar structures and biological activity. They are often denoted with a quick molecular sketch that looks like a series of numbers hovering around a piece of chicken wire. The family includes 210 different polychlorinated dibenzo-para-dioxins (PCDDs) and polychlorinated dibenzo-furans (PCDFs). The famously destructive PCBs, or polychlorinated biphenyls, are also related. Out of the three groups, there is a subset of 29 compounds that have been identified as having varying levels of "dioxin-like" toxicity. The dioxin TCDD tops the charts and is the most lethal human made poison next to radioactive waste. Tiny, tiny amounts can wreak havoc in biological systems.

Dioxin is a potent human carcinogen. It has also been linked to cardiovascular disease, diabetes, compromised immune system, endometriosis, disruption of the endocrine system (including the hypothalamus, pituitary, thyroid, parathyroid, adrenal, and reproductive glands).

Dioxin is a persistent, bio-accumulative toxin, which means it isn't broken down into safer chemicals, and it is concentrated in the food chain (with humans typically at the top). The invisible poison has a tendency to take to the air and can ride the winds as far as our remote polar regions. Decades ago, scientists who were trying to find humans who might be uncontaminated, were horrified to discover that Inuit people had far greater concentrations of these chemicals in their fat than we do - a testament to their amazing drift potential.

Dioxins are difficult and expensive to measure. Annual dioxin testing done for Catalyst, indicates emissions only at the time of testing but is used to calculate annual emissions. It is not clear how many times in a year there are spikes due to combustion irregularities, including start-up/shut-down procedures. We do know, however, that the tests themselves are still highly variable. In PAPRICAN's (Pulp and Paper Research Institute of Canada) 2003 executive summary of "Investigations into the Variability and Control of Dioxins Formation and Emissions from Coastal Power Boilers" it says, "The results from single tests on any of the coastal power boilers vary by a factor between 4 and 45 and four of the 8 mills have measured emissions in the last three years that exceed the Canada Wide Standards for existing facilities (0.5 ng TEQ/m3 @11% O2)."

In Europe, testing for dioxin/furan is now done by continuous sampling technology. This may be the only way to get accurate measurements and trends.