One treats people in waves from terrible apartheid riots (14)

I believe the answer is:

radiotherapist

'one treats people in waves' is the definition.
(someone who treats patients with radio waves)

'terrible apartheid riots' is the wordplay.
'terrible' indicates an anagram.
'apartheid'+'riots'='apartheidriots'
'apartheidriots' is an anagram of 'RADIOTHERAPIST'.

'from' is the link.

I've seen this clue in The Guardian.

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