https://ehjournal.biomedcentral.com/articles/10.1186/s12940-015-0006-y
https://ehjournal.biomedcentral.com/articles/10.1186/s12940-015-0004-0
https://ehjournal.biomedcentral.com/articles/10.1186/1476-069X-14-13
https://ehjournal.biomedcentral.com/articles/10.1186/1476-069X-14-15
https://ehjournal.biomedcentral.com/articles/10.1186/s12940-015-0003-1
https://ehjournal.biomedcentral.com/articles/10.1186/1476-069X-14-16