Manganese in the urban atmosphere: identifying anomalous concentrations and sources.
OBJECTIVE
Industrial emissions can raise urban background levels of inhalable Mn particles in an order of magnitude above normal, eclipsing the contribution made by natural sources and traffic.


METHODS
The source of such emissions can be identified using a multidisciplinary approach which integrates ICP-MS chemical analyses of PM(10) and PM(2.5) samples with positive matrix factorization source apportionment modelling, scanning electron microscopy and meteorological data.


RESULTS
We apply this methodology to data from Santander (N Spain), where morning Mn-bearing industrial contamination sourcing from the SW is returned towards the city by afternoon NE sea breezes. This wind direction reversal carries the industrial pollution plume inland, detectably raising urban background levels of MnPM(10) in the town of Torrelavega 20 km away. Industrially sourced daily urban background Mn levels at Santander reach >1,000 ng/m(3), average >150 ng/m(3).


CONCLUSIONS
We demonstrate the anomalous nature of such concentrations by comparing them with >2,500 PM(10) chemical analyses of ambient PM(10) from other sites in Spain which show how current background Mn levels in urban air typically average only 10 ng/m(3), rising to 20-25 ng/m(3) in city traffic sites. Daily levels of atmospheric Mn PM(10) only rarely exceed 50 ng/m(3), usually during desert dust intrusions which, in extreme cases (such as Canary Islands "calima" events from Africa) can produce Mn concentrations of 100-125 ng/m(3).
Moreno
Teresa
T
Institute of Environmental Assessment and Water Research, IDAEA, CSIC, C/Jordi Girona 18, 08034 Barcelona, Spain. teresa.moreno@idaea.csic.es
Pandolfi
Marco
M
Querol
Xavier
X
Lavín
Javier
J
Alastuey
Andrés
A
Viana
Mar
M
Gibbons
Wes
W
D000393:Air Pollutants / Q000032:analysis* / Q000737:chemistry; D000397:Air Pollution / Q000706:statistics & numerical data*; D016208:Databases, Factual; D004784:Environmental Monitoring; D006801:Humans; D007220:Industrial Waste / Q000032:analysis; D008345:Manganese / Q000032:analysis* / Q000737:chemistry; D013058:Mass Spectrometry; D019216:Metals, Heavy / Q000032:analysis / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D015233:Models, Statistical; D010316:Particle Size; D052638:Particulate Matter / Q000737:chemistry*; D015203:Reproducibility of Results; D012621:Seasons; D013030:Spain; D013054:Spectrophotometry, Atomic; D013997:Time Factors; D014504:Urban Health; D014919:Wind
D000393:Air Pollutants; D007220:Industrial Waste; D019216:Metals, Heavy; D052638:Particulate Matter; D008345:Manganese