A new study has linked pollutants and poverty with changed in the ratio of boys and girls born to millions of parents.br The Guardian reports that half the br United States' population and the entire br Swedish population took part in the study.br The study found that mercury, chromium and aluminum pollution was linked to more male births, while lead pollution was correlated with more female births. .br It also found that measures of poverty, like living near high number br of vacant buildings and fast food restaurants, were also br linked with statistically significant changes to sex ratios. .br The Guardian points out that the research found correlations between various factors and sex ratios of birth, not a cause and effect relationship. .br This is a list of suspects to investigate,br and all the suspects have some br credible evidence, but we’re br very far from conviction, Andrey Rzhetsky, Lead Researcher br at the University of Chicago, via The Guardian.br There are a lot of myths about sex ratio and birth, but when you dig into the research, it turns out that everything that was tested on real data was done on relatively small samples [risking spurious correlations], and some statements are not founded in observations at all, Andrey Rzhetsky, Lead Researcher br at the University of Chicago, via The Guardian.br The new research was published in br the journal Plos Computational Biology.br It is the first investigation into a number of chemical pollutants, as well as other environmental factors, using a large dataset from two continents. .br According to 'The Guardian,' 150 million people in br the U.S. participated in the study over eight years. .br In Sweden, 9 million people br participated over 30 years.