By | February 14 2013 1:08 PM

When the clock struck 12 on Feb. 9, the eve of the Lunar New Year, city skylines across China lit up with fireworks in celebration of the start of the nation’s biggest holiday, the Spring Festival. And despite efforts to be aware of the massive pollution the fireworks cause, levels of PM2.5 -- especially toxic airborne particles -- are still dangerously high.