Table 2 Simple regression coefficients for annual age-standardised lung cancer incidence rates per 100 000 women, according to solar UVB irradiance, total cloud cover, anthropogenic aerosol optical depth, and per capita cigarette consumption, 111 countries that reported cigarette use, GLOBOCAN, 2002

Variable		R²	Regression coefficient	Standard error		t		p
Solar UVB irradiance*	0.35		−1.402	0.145	−9.69		<0.001
Total cloud cover†	0.39		23.188	2.208	10.5		<0.001
Anthropogenic aerosol‡	0.12		14.659	3.068	4.78		<0.001
Cigarette consumption§	0.66		0.0188	0.001	14.55		<0.001

*W/m² at vernal equinox, 297–320 nm. Source: Calculated using a standard algorithm from Columbia University for UVB irradiance according to latitude and date.17
†Mean percentage of sky covered with clouds, winter solstice. Source: International Satellite Cloud Climatology Project.15
‡Anthropogenic aerosol optical depth. Source: NASA MODIS project.14
§Based on per capita cigarette consumption data from the World Health Organisation, computed as sex-specific cigarette consumption.12