Fate in the Environment and Long-Range Atmospheric Transport of the Organophosphorus Insecticide, Chlorpyrifos and Its Oxon - Reviews of Environmental Contamination and Toxicology - page 36

Table 1 Reported concentrations of CPY in air in N America
Location and dates of sampling Concentration (ng m −3 ) Reference

CANCUP data for 8 sites in
Canada 2004-2005, values
range from areas of
application to distant areas

0.08-22 Yao et al. ( 2008 )

Passive air samples in Ontario
2003-2005

0.0003-0.06; median 0.007; 73%
FOD a

Kurt-Karakus et al.
( 2011 )

Iowa 2000-2002 Average 1.0, 19% FOD 1.4 at

1A—AM Site, 0.88 at Hills

Peck and
Hornbuckle
( 2005 )

Mississippi River Valley 1994 0.43 Majewski et al.

( 1998 )

Chesapeake Bay 2000 0.015-0.670 Median 0.110 FOD

87%

Kuang et al. ( 2003 )

Bratt's Lake (Saskatchewan)
and Abbotsford (British
Colombia)

Mostly 10-100 with 3 concentra-
tions exceeding 100 and a
maximum of 250 in Aug 2003
at Bratt's Lake near area of use
but max only 1.38 in Jul 2005.
Concentrations in Abbotsford,
an area of lesser use all <0.26 in
2004 and 2005

Raina et al. ( 2010 )

Mississippi River Valley FOD 93, MS 35%, Iowa City 90%,

Cedar Rapids 50%, Minneapolis
10%, Princeton MN 3%

Foreman et al.
( 2000 )

Central Valley (CA) and Sierra
Nevada

CPY up to 180 and CPYO up to 54,
lesser concentrations in Sequoia
NP

Aston and Seiber
( 1997 )

CPY and CPYO in air in
Sequoia NP

0.16-17.5 LeNoir et al.

( 1999 )

a FOD = frequency of detection

2.1 Chlorpyrifos and Chlorpyrifos-Oxon

Evidence that CPY is subject to LRT is provided in reports of concentrations in air
and other media at locations remote from sites where CYP is applied in agriculture
(Tables 1 , 2 , 3 and 4 ). Notable are studies conducted in the intensely agricultural,
Central Valley of California and adjacent National Parks. CTDs of several pesti-
cides, including CPY have been estimated (Muir et al. 2004 ). Results of these mod-
eling exercises have suggested a CTD of 280-300 km for CPY, the narrow range
being the direct result of close similarities between the model equations. Monitoring
observations of concentrations of CPY in air close to and carried downwind from
application areas are in general accord with these distances. Also in accord are
monitoring data reflecting deposition in foothill and mountainous terrain, especially
in the Sierra Nevada of California.