Table 7.

Correlation of urinary THPI measures with the original AHS pesticide exposure intensity algorithm and with the adjusted algorithm

THPI exposure measurea	n	%>LOD	Original algorithm		Adjusted algorithm
			βb	P-value	βb	P-value
24-h conc., μg l−1	130	NAc	0.0001	1.0	0.0307	0.08
24-h mass, μg	130	NAc	−0.0035	0.84	0.0284	0.14
Mass, first-morning, Day 1, μg	140	61.4	−0.011	0.63	0.0411	0.12
Conc., first-morning, Day 1, μg g−1 creatinine	140	61.4	0.0016	0.94	0.0498	0.04
Excretion rate, overnight (Day 0 to Day 1), μg h−1	117	59.8	−0.015	0.56	0.0367	0.15

Conc., concentration; LOD, limit of detection; NA, not applicable.

^aUrinary THPI levels previously reported in Hines et al. (2008).

^bThe estimated regression coefficient and P-value were computed using MLE via PROC NLMIXED with person treated as a random effect. The data were left-censored at the LOD. The log-normal distribution was specified in the model. Use of MLE for treating censored data was not feasible for the 24-h urine measurements because several samples had been summed to create the 24-h value; instead, values below the LOD were replaced with LOD/2, the samples summed, and the β and P-value estimated via the PROC MIXED procedure with person treated as a random effect.

^cThe percentage of days where all samples comprising the summed 24-h total had THPI levels below the LOD was 24% for airblast and 55% for hand spray.