Comprehensive study of lead pollution in Shanghai by multiple techniques

Area of Science:

• Environmental Science
• Atmospheric Chemistry
• Analytical Chemistry

Background:

• Particulate Matter (PM10) is a significant air pollutant.
• Lead (Pb) in PM10 poses environmental and health risks.
• Understanding lead sources is crucial for effective pollution control.

Purpose of the Study:

• To determine atmospheric lead concentrations in Shanghai's PM10.
• To identify the chemical species of lead particulates.
• To pinpoint the primary sources of lead pollution.

Main Methods:

• Analysis of PM10 aerosol samples using Particle-Induced X-ray Emission (PIXE).
• Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) for elemental analysis.
• X-ray Absorption Fine Structures (XAFS) to determine lead chemical forms.
• Isotope ratio and chemical mass balance calculations for source apportionment.

Main Results:

• Average lead concentrations in PM10 were 369 ng.m-3 (2002) and 237 ng.m-3 (2003).
• Major lead chemical species identified were lead chloride (PbCl2), lead sulfate (PbSO4), and lead oxide (PbO).
• Key sources identified: coal combustors, iron/steel plants, and vehicle exhausts.

Conclusions:

• Coal combustion was the dominant source of atmospheric lead pollution in Shanghai.
• This dominance persisted even after the phase-out of leaded gasoline in 1997.
• The findings highlight the need for targeted emission controls on industrial sources.