AUTHOR=Häder Donat P. TITLE=A grand challenge for environmental toxicity: what are the permissive limits of toxic pollutants in the environment? JOURNAL=Frontiers in Environmental Science VOLUME=1 YEAR=2013 URL=https://www.frontiersin.org/journals/environmental-science/articles/10.3389/fenvs.2013.00002 DOI=10.3389/fenvs.2013.00002 ISSN=2296-665X