[en] Samples of topsoils and vegetation from a wide distribution of sites in West Malaysia have been analysed for their ¹³⁷Cs content by gross gamma-ray spectrometry using a Ge(Li) detector. The levels of contamination ranged up to 6.7 nCi/m² in soils from peak locations and up to 24 nCi/m² in one nonpeak location. There was an indication of a possible preferential scavenging effect by rainfall during the south west monsoon period (May to September) making levels in the western rainfall zone slightly higher than in the eastern rainfall zone. The levels in canopy leaves were shown to be strongly correlated with the presence of epiphyllae colonies on their surfaces, causing an enhanced interception of aerosols. The highest level recorded in canopy leaves was 3.7 pCi/g and corresponded to 70% of the leaves harboring epiphyllae colonies. Levels from epiphytic lichens and mosses ranged from 0.23 to 1.3 pCi/g and up to 4.2 pCi/g for ferns. The data on soil samples suggest that West Malaysia has intercepted a minimum of 522 Ci of ¹³⁷Cs from past nuclear weapons testing as of March 1974. (author)