Air pollution - safe ground level concentrations A.M Coetzee Clean Air Journal · Volume 5, Issue 5 (1981) DOI: 10.17159/caj/1981/5/5.7244 Abstract No abstract Article information Published3 June 1981 Languageen PublisherAcademy of Science of South Africa LicenseNo license URL DOI10.17159/caj/1981/5/5.7244 Journal ISSN1017-1703; 2410-972X