Table 5.

Extractable organic fluorine levels from tap water samples matched by city at five locations in Massachusetts (MA1 – MA5) in 1989–1990^a and 2016^b

Extractable organic fluorine (ng/L)	MA1		MA2		MA3		MA4		MA5
	1989–1990	2016	1989–1990	2016	1989–1990	2016	1989–1990	2016	1989–1990	2016
PFOA	0.2	6.2	0.5	1.7	0.9	4.8	0.6	0.9	1.3	0.9
PFOS	0.4	1.6	0.4	0.8	1.2	4.2	0.5	0.3	0.6	0.3
Other PFCAs	0.1	7.4	0.8	4.2	1.3	9.6	0.6	1.7	0.0	5.1
Other PFSAs	0.3	4.3	0.3	1.7	1.5	5.6	0.2	0.7	0.4	0.1
PFOS precursors	0.0	0.0	0.3	0.0	0.0	0.0	0.0	0.0	0.0	0.0
Unknown	6.7	135.6	19.8	105.2	2.9	39.4	0.2	58.5	5.4	9.6

^a1989–1990 tap water samples were collected from five participants’ home addresses, one sample at each location.

^b2016 tap water samples were collected in the cities from the same municipal water supplies as original participant’s homes. Two samples were collected at each location.