Table 1.

Effects of purification on the levels of contamination by E. coli in shellfish (MPN/100g). Data from the two harvesting areas were averaged.

Month	Mytilus galloprovincialis		Ruditapes decussatus
	Before purification	After purification	Before purification	After purification
May 2011	<18	40	<18	<18
July 2011	40	40	40	40
November 2011	40	40	61	40
March 2012	130	130	40	40
May 2012	61	40	40	40
Total	54	58	36	32