Table 6.

Comparison of selected pesticides measured in soil samples collected at childcare centers in the United States.

Reference	Geographic Location	Chemical Analytes
		Number of Samples	Chlorpyrifos (µg/kg)	cis-Permethrin (µg/kg)	trans-Permethrin (µg/kg)
This Study	Pacific Northwest, USA	33	42a	2.3a	2.1a
Morgan et al. [12]	North Carolina	13	NRb	<1.0–2.55c	<1.0–2.2c
Morgan et al. [10]	Ohio	16; 14	NRb	<1.0d	<1.0d
Tulve et al. [8]	USA	117	24 (14); 1200e	5 (1); 130e	6 (1); 140e
Morgan et al. [11]	North Carolina	13	<1.0d	NRb	NRb
Wilson et al. [13]	North Carolina	4	<2d	NAf	NAf

^aMeasurement > RL only found in one sample.

^bNR = not reported.

^cRange.

^dMethod detection limit.

^eMean (standard error); maximum.

^fNA = not analyzed.