The National Pollutant Inventory

1
The National Pollutant Inventory

• Late 1992 announcement
• February 1994 discussion paper
• Pollution Release and Transfer Inventories
• March 1997 Technical Advisory Panel
• May 1997 Technical Report
• January 1999 report to NEPM process

2
Pacific Air and Noise

• Began with 180 substances
• Scored them 0-3 on - relative hazards
• - environmental impact
• Process seen as simplistic and ignoring human
  health impacts
• Omissions metal speciation, agricultural uses,
  VOCs

3
New Approach

• Start with 400 substance
• Rank on risk hazard x exposure
• Transparency guaranteed
• Scores 0-3 assigned
• European risk phrases used for hazard
• Professional judgment occasionally
• Its not arithmetic!

4
Scoring details

• hazard human health environment
• human health ½(acute chronic)
• chronic includes reproductive and carcinogenic
• environment acute chronic

5
More scoring details

• exposure 1/6(point diffuse) x bioavail.
• diffuse 1/6(volume x environmental fate)
• exposure, human health hazard and environmental
  hazard each normalised 0-3
• risk hazard x exposure maximum 18
• scores rounded to two significant figures

6
Some examples

• oxides of nitrogen (1.5 3) x 3.0 13.5
• dichloromethane (1.5 1.3) x 2.8 7.8
• xylenes (1.3 1) x 3.0 6.9
• 1,3-butadiene (2.7 0.7) x 2.0 6.8
• benzene (2.3 1.0) x 2.0 6.6
• formaldehyde (1.5 1.2) x 1.3 3.6

7
Advice from the TAG

• this methodology works well in restricted
  fields
• reporting thresholds are more judgment based
• Cut the list only at defined break points
• Beware of politically active substances
• Ag-vet chemicals need further attention

8
Air Toxics or HAPs

• Started with NPI list of 90
• Eliminated criteria pollutants, lower priority
  substances, most solids
• Put aside indoor air considerations
• Haggled over the list of 32 substances
• Compared list with Vic EPA 24 HAPs and US EPA
  33 urban air toxics

9
Recommended Air Toxics

• dichloromethane (5)
• cadmium cpds (6)
• xylenes (9)
• arsenic cpds (10)
• trichloroethylene (12)
• 1,3-butadiene (13)
• benzene (14)
• PAHs (18)
• deferred

• methyl ethyl ket. (21)
• methyl isobut. ket (28)
• fluorides (31)
• toluene (33)
• toluene diisocyan. (34)
• mercury cpds (35)
• nickel cpds (54)
• formaldehyde (55)

10
Quotations abound ...

• Chemophobia is deeply rooted in western
  culture ... (and)was accentuated in the 1960s
  and 1970s by a series of industrial chemical
  accidents and government cover-ups. Steeped in
  the cause and effect paradigm, science
  professionals did not recognize the validity of
  public fears (which) were vaulted into the
  political arena by activists and widespread
  publication of controversial papers suggesting
  doubt in the scientific method.
• Kate Lindsay and Daniel W. Smith (Canada 2002)

11
but solutions are hard to find

• The solution is complex and systemic in nature.
  There may never be facts, only inference
  based on expert knowledge.
• Kate Lindsay and Daniel W. Smith (Canada 2002)
• Should we acknowledge this by giving up our
  attempt to use a well known four-letter word in a
  specialist context?