What Comes Out Where in the Air
at a Chlorine Dioxide Bleaching Kraft Pulp Mill; How Much, and What Are the Health Impacts (Who Does It Kill?)
Where: digesters, secondary treatment plant
Health: Precursor to fine particulate formation. Irritant.
Where: Lime kiln, power boilers.
Health: human visual impact at 50 ppm for one hour, death at more than 750 ppm, vegetation impact at higher levels.
Where: Effluent treatment system, power boilers.
Health: Greenhouse gas.
Where: Recovery boiler.
Health: Potential neurotoxin, acute (short-term) inhalation of high concentrations of carbonyl sulfide may cause narcotic effects in humans. Carbonyl sulfide may also irritate the eyes and skin in humans.
Chlorine and Chlorine dioxide
Where: Generation systems, extraction stage scrubbers, bleach plant "upsets" such as explosions. A BC study funded by Health Canada and the Workers' Compensation Board showed that chlorine was present in almost areas of the mill, including the wood yard, although the mill was 100% chlorine dioxide bleaching. (In other words, the chlorine dioxide breaks down to release chlorine into the air and from the pulp.) Chlorine and chlorine dioxide exposures showed significant short term peaks (both over 20 ppm) which exceeded regulatory limits, and posed a health risk, although these peaks could not have been detected using shift-long measurements as is the norm. Wood dust also posed a health problem.
Health: Chlorine is a severe short and long term respiratory irritant at levels above 1 ppm (odour threshold 60-200 ppb); chlorine dioxide is a severe short and long term respiratory irritant at levels above 0.1 ppm (odour threshold 100 ppb - NIOSH, 1987). Both compounds kill at high levels. The BC Workman's Compensation Board has lowered the 8 hour exposure level for chlorine to .5 ppm. The characteristic response to short term chlorine and chlorine dioxide exposure is Reactive Airway Dysfunction Syndrome (RADS), airway inflammation and bronchial hyper-responsiveness, which may last for three years or more, and can result from one acute exposure. "Adverse effects on immune system, blood, heart, and respiratory system in laboratory studies."-Taking Stock.. In pulp mills, chlorine can react with other gases - Total Reduced Sulphur, turpentine, and ammonia, in the last case producing CEPA-Toxic chloramines.
Where: Effluent treatment system, possibly bleach plant
Health: Recognized carcinogen, suspected respiratory, cardiovascular or blood, liver and kidney toxicant, endocrine and neurological disruptor.
Dioxins and Furans
Where: Recovery boiler, power boiler if burning "salty" hog fuel
Health: Health effects associated with dioxin and the chemically-similar PCBs, probably through action on the chemical messengers of the body, and passed on through the generations, include reproductive effects, from low sperm count to endometriosis; hyperactivity; allergies and immune and endocrine system malfunctions; diabetes; low birth weight, poor motor co-ordination and lower IQ for children. Dioxin is classified as a human carcinogen by the International Agency for Research on Cancer and it is recognized as a tumour promoter, along with its other roles in modifying and disrupting growth functions.
Adverse Health Effects
Adults: Skin disease, Immunosuppression,Respiratory effects, Cardiovascular effects, Liver effects, Reproductive toxicity, Carcinogenicity 2B
Fetus: Learning behaviour, Development of reproductive system, Immune system
* USEPA 1999
Hydrogen chloride (part of PM?):
Where: Recovery boiler
Health: Suspected gastrointestinal or liver toxicant, respiratory and skin or sense organ toxicant
Where: Recovery boiler, oxygen delignification systems, effluent treatment system. Methanol has been accepted by the US EPA as a surrogate monitoring measurement for a wide range of the Hazardous Air Pollutants (chlorinated compounds) which the US requires polluters to report, and the US Cluster Rules now require mills to collect these gases and burn them in the fire zone of the Recovery boiler:
Health: Suspected developmental toxicant, neurotoxin, gastrointestinal or liver toxicant
Nitrogen Oxides (NOx)
Where: Lime kiln, recovery boiler, power boiler, gas turbines, brown stock washers.
Health: NO2 is acute respiratory irritant at 1 ppm for 15 minutes. Harmful Air contaminant, Precursor to smog, ground level ozone, fine particulate and acid rain. Harmful to humans, vegetation growth and health.
Where: Recovery boiler, lime kiln, smelt dissolving tank, power boilers, wood chip yard, dust from landfill. Particulate can be material, such as wood, lime, or road dust, or chemical compounds created with carbon, metallic oxides and salts, acids, oils, etc.
Health: The lungs and respiratory tract can expel large Particulate. Greatest health impact is felt from particles with smallest size - designated PM 10 (microns) or less, and especially PM 2.5 - which penetrate the lungs and stay there, frequently delivering a toxic load to the body and guaranteeing the unwelcome visitor will stay. Fine Particulate is linked to serious health impacts including chronic bronchitis, asthma, and premature deaths. PM 2.5 has been recognized to have the potential for the greatest health impact on a larger segment of the general public.
Secondary particles are formed through chemical reactions involving the precursors NOx, VOCs, sulphur oxides (SOx), and ammonia (NH3).
US Federal standard 150 ug/m3; health impacts such as children's absenteeism due to asthma at 50ug/m3. BC has set a new air quality objective of 25 ug/m3 for PM 2.5; the Canadian Council of Ministers of Environment have determined a Canada Wide Standard for PM, focused on the fine fraction of PM, smaller than 2.5 microns, known as PM 2.5 of 30 gm/m3 averaged over 24 hours, to be achieved by 2010.
Where: Power boilers, brown stock washers, chip bins, effluent treatment system
Health: Smog precursor, kills fish, toxic to kidneys of humans, also wide range of sensitive effects including to blood, immune and nervous systems.
Sulphur oxides (SO2, SO3 and solid sulphates)
Where: Recovery boiler, lime kiln, power boilers, brown stock washers, chip bins. Anywhere sulphur containing compounds, including oil and gas, are burned.
Health: Irritating to eyes and respiratory system at 5 ppm for 10 minutes. SOx is a precursor to fine Particulate Matter formation. Sulphuric acid is implicated in bronchitis, emphysema, eye, nose, and stomach irritations, and possible lung cancer in exposed workers.
Total Reduced Sulphur compounds , including hydrogen sulphide, methyl mercaptain, di-methyl sulphide, and di-methyl disulfide.
Where: Recovery boiler, Non-Condensible Gas collection systems durin, effluent treatment system g upsets at 75-300 lb/hour, lime kiln, smelt dissolving tank, digesters, power boilers
Health: - extraordinarily foul-smelling, toxic, heavier than air. H2S Irritates eyes at 50 ppm, causes death at 100 ppm. Human nose detects at about 1 ppb. See also Dr. Hirsch's testimony.
Miscellaneous: alcohols, terpenes, acetaldehyde, nitrates, fungi (aspergillus fumigatus and a. versicolor) bioaerosols (endotoxin), benzene and assorted substituted benzenes, chlorinated benzenes and phenolics, guaiacols, and other Volatile Organic Compounds, many of them unquantified and unidentified, but including dichloroacetic acid methyl ester, 2,5,-dichlorothiophane, styrene, toluene and xylenes, all varying from day to day, depending on feed stock and "upsets" anywhere in the mill.
Simons discusses the US Clean Air Act's 189 Hazardous Air Pollutants and says the emissions from pulp and paper derive from chemicals used or by-products, and include: alcohols, aldehydes, benzene, ketones, polyaromatic hydrocarbons (PAH) and phenolics. Simons cites a US list which pinpoints acetone, ammonia, chlorine, chlorine dioxide, chloroform, formaldehyde, hydrochloric acid, methanol, sodium hydroxide, and sulphuric acid as trace air contaminants of concern.
In Canada, in 1999 Improved reporting by the Pulp and Paper Industry The Canadian Pulp and Paper Association, together with the U.S. based National Council for Air and Stream Improvement Inc. (NCASI) developed a guidance manual for reporting to the NPRI. The NCASI manual was produced to assist mill staff in completing NPRI reports by making available the most recent information and methods for identifying and estimating releases of pollutants from pulp and paper mills. In using the handbook, many pulp and paper facilities reported releases from more sources in 1999 than in the past, and as a consequence, higher releases of NPRI substances. However, this does not necessarily mean that releases by the pulp and paper industry have actually increased. This indicates better reporting in terms of number of substances and more accuracy in calculating releases. Some pulp and paper mills have also re-calculated releases for previous years and have indicated so in the comments field of the NPRI Reporting Software. A check of the comments fields is required to understand the changes in reporting from this sector.
The National Office of Pollution Prevention of Environment Canada is working on an analysis of the data reported by the pulp and paper industry to the NPRI. This analysis will summarize reporting for 1999 and the re-calculation of NPRI releases by the pulp and paper industry for the years 1995-1998 with the use of the NCASI manual. The National Office of Pollution Prevention has prepared a backgrounder detailing the changes in NPRI reporting between 1998 and 1999.
The data charts below are seven years old, but give the general range of air pollut
1995-98 Air Emission Data Calculations (tonnes of pollutant per year / air dried tonnes of pulp per year x 1000 = kilograms of pollutant per air dried tonne of pulp)
1995-98 Air Emission Data Summary (kg pollutant per year per air dried tonne of pulp)
For more information and prelinimary 2004 data see
You can download the useful and straightforward Citizens' Guide to
the NPRI from the publications section of the Canadian Institute for
Environmental Law and Policy site at
ASL Analytical Service Laboratories Ltd., Investigation of Chemicals and Bioaerosol Emissions From Pulp Mill Effluent Treatment Systems, Pulp and Paper Advisory Committee, Nov 1997
Astrakianakis, George, et al. Industrial Hygiene Aspects of a Sampling Survey at a Bleached Kraft Pulp Mill in British Columbia, AIHA Journal, Oct 1998, 694-705, Vol: 59
Commission for Environmental Co-operation, Taking Stock, Appendix C: Human Health Effects and Uses of Chemicals on the top 25 lists.
Jamieson, Lynne, Occupational Health and Safety in Pulp Mills Using Chlorine, Chlorine Dioxide, Hydrogen Peroxide and Ozone, The Natural Resource Council of Maine Jan. 1997
Occupational and Environmental Risk Management Group (COFI), Chlorine/Chlorine Dioxide: Review of Health Effects, Forest Industry Health Research Program, Feb. 1997
Ritchlin, Jay and Johnston, Paul, Zero Discharge: Technological Progress Towards Eliminating Kraft Pulp Mill Liquid Effluent, Minimising Remaining Waste Streams and Advancing Worker Safety, Reach for Unbleached!, 1998 Download the pdf
H.A.Simons Ltd., A Technical Background Information Document on Pulp and Paper Mill Air Emissions, BC Ministry of Environment, Oct. 1994.
Jacques Whitford, Technical Review of the ARET release from the Pulp and Paper Industry, Environment Canada, Project No. 80011, April 19, 1999