Amazon Forest Fires Between 2001 and 2006 and Birth Weight in Porto Velho

Birth weight data (22,012 live-births) from a public hospital in Porto Velho (Amazon) was used in multiple statistical models to assess the effects of forest-fire smoke on human reproductive outcome. Mean birth weights for girls (3,139 g) and boys (3,393 g) were considered statistically different (p-value < 2.2e-16). Among all models analyzed, the means were considered statistically different only when treated as a function of month and year (p-value = 0.0989, girls and 0.0079, boys) . The R (2) statistics indicate that the regression models considered are able to explain 65 % (girls) and 54 % (boys) of the variation of the mean birth weight.