Compelling new evidence shows Mount Isa mine emissions are contaminating the city and are the cause of childhood lead poisoning

17 June 2013

Despite  upgrades  to  technology  and  ore  management  techniques,  new  and  compelling  research shows that the combined effects of historic and contemporary emissions are the definitive cause of environmental lead contamination in the city of Mount Isa.

The Macquarie University study used powerful  lead  isotopic  fingerprinting  techniques  to  debunk  the  long‐propagated  myth  that  the contamination in the city is due to natural mineralisation from regional geology.

The  study,  published  today  in  Environmental   Pollution,  identified  the  sources,  pathways  and relative  risk of environmental  lead  at Mount  Isa via analysis  of the concentrations  and  isotopic compositions of lead in soil, aerosols, dust and rock.

“The data we’ve generated from this research provides conclusive and unequivocal information for the state’s regulatory authorities who are responsible  for Mount Isa’s environmental  remediation and human health protection,” says Professor Mark Taylor.

“Xstrata Pty Ltd and Queensland Government agencies have long disputed the industrial source of environmental lead, arguing that the elevated lead in local children comes from natural surface exposures  of orebodies.  This is fundamentally  and scientifically  incorrect  and this study provides sufficient evidence to bring closure to that distracting debate.”

“This research shows the naturally occurring argument is a ‘myth’ for several reasons:

•     Environmental samples of property dust wipes, aerosol particulates and surface soils from within the city area contain lead that is virtually indistinguishable from the Mount Isa  lead orebody.
•     Sub‐surface   soils  and  rocks  from  the  urban  area  have  completely   different   isotopic signatures to the Mount Isa lead orebody, showing that contamination  cannot have come from in situ weathering of bedrock but from atmospheric deposition of contaminants.
•     There is no substantial  lead source from natural surface exposures  of minerals  in Mount Isa’s urban area. This   new   study   confirms   and   consolidates   earlier   research   by   Macquarie   University   that demonstrated  mine emissions were the cause of blood poisoning amongst the city’s children.

The methods and research design used in this study are of direct relevance to other mining towns in Australia elsewhere in the world, where mining and industrial activities pose a serious risk of harm and the source and cause of contamination is disputed.

“Families in Mount Isa need to be informed of the exposure sources and to make informed choices about their lives and any risks associated with their place of work, recreation or inhabitation.  The people  of Mount  Isa  deserve  the  same  protection  from  air,  soil  and  water  contamination  as is afforded to the rest of Queensland and Australia” says Professor Taylor.

Professor Taylor’s research team has published 17 peer-reviewed papers over the last 8 years, examining lead and other metals around Mt Isa.

For more information, a PDF summary of their research is available for download here.

Identification  of  environmental   lead  sources  and  pathways  in  a  mining  and  smelting  town: Mount  Isa,  Australia,  Environmental  Pollution  (2013),  A.K.  Mackay,  Macquarie  University;  M.P. Taylor,  Macquarie  University;  N.C.  Munksgaard,  Charles  Darwin  University;  K.A.  Hudson-­Edwards, UCL-­Birkbeck, University of London; L. Burn-­Nunes, Curtin University.

Filed under: Research Science & nature