RT Journal Article SR Electronic T1 Effects on health of prolonged exposure to low concentrations of carbon monoxide JF Occupational and Environmental Medicine JO Occup Environ Med FD BMJ Publishing Group Ltd SP 708 OP 711 DO 10.1136/oem.59.10.708 VO 59 IS 10 A1 Townsend, C L A1 Maynard, R L YR 2002 UL http://oem.bmj.com/content/59/10/708.abstract AB