Table 3.

Relative changes (%) per year in untransformed blood VOC concentrations (µg L⁻¹) at various quantiles.^a

VOCs	1988–1991 vs. 2003/2004			1988–1991 vs. 1999/2000			1999/2000 vs. 2003/2004
	0.5	0.75	0.95	0.5	0.75	0.95	0.5	0.75	0.95
Aromatics
Benzene	−3.8	−4.3	−3.3	5.2	−1.2	0.1	−18.2	−14.8	−12.4
Toluene	−5.6	−5.7	−4.7	−1.9	−2.9	−1.3	−15.3	−14.8	−12.9
Ethylbenzene	−4.2	−4.9	−4.9	−4.2	−4.2	−3.2	−6.5	−9.4	−11.1
m,p-xylene	−2.5	−3.5	−4.5	−0.8	−1.8	−2.4	−6.3	−7.9	−10.8
o-xylene	−5.5	−5.5	−5.6	−7.9	−6.8	−5.3	−2.1	−6.4	−10.9
BTEX	−4.4	−4.6	−4.2	−2.1	−1.6	−0.8	−10.8	−12.0	−11.9
Styrene	−3.9	−2.7	−3.1	0.5	0.1	0.6	−12.3	−8.2	−10.1
THMs
Chloroform	−3.9	−3.6	−3.9	3.5	6.3	2.5	−17.5	−18.1	−17.0
BDCM	−5.0	−5.6	−3.4	−6.5	−3.5	−3.0	−3.1	−2.6	−6.8
DBCM	−6.3	−3.0	−4.8	−8.1	−6.6	−5.8	−13.5	−10.8	−5.9
Bromoform	−7.9	−7.5	−7.0	−11.9	−11.2	−10.6	2.8	−1.0	1.1
∑THM	−5.9	−5.4	−3.8	−5.4	−2.1	2.7	−12.2	−14.4	−13.9
Others
1,4–DCB	−3.5	−3.7	−3.7	−2.3	−2.5	−4.8	−9.0	−9.8	−0.8
PCE	−3.2	−6.2	−6.4	−2.7	−4.8	−5.1	−5.3	−14.8	−15.4

Relative changes of VOC levels per year between study period at each percentile.

Bold type means statistically significant trend (p < 0.05).

^aExcludes 1988–1991 data for toluene, ethylbenzene, m,p-xylene, o-xylene, BTEX, styrene, bromoform, ΣTHM and PCE.