      UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C.  20460

                                                                        
                                                                        
            OFFICE OF     

PREVENTION, PESTICIDES

AND TOXIC SUBSTANCES

March 6, 2006

MEMORANDUM

SUBJECT:	PCNB:  HED Revision of golfer Risk Assessment  DP Barcode 

		D 327362, Pc Code 056502.

From:		Seyed Tadayon, Chemist

		Reregistration Branch 3

		Health Effects Division [7509C]

			

Through:	Danette Drew, Senior Scientist

		Reregistration Branch 3

		Health Effects Division [7509C]

To:		Diana Lock, Risk Assessor

		Reregistration Branch 2

		Health Effects Division [7509C]

		

This is a revision of the original golfer Exposure Assessment  for PCNB,
(S.  Tadayon November 15, 2004 DP Barcode D291283 ).  This revision  has
been done for the assessment of golfers using recently submitted golf
course maintenance study data by Agricultural Re-entry Task Force
(ARTF).

Background

A Turf Transferable Residue (TTR) study (MRID# 44687101) was submitted
in support of the re-registration of PCNB but, since there was no
concurrent transfer coefficient measurement done in this study it was
found to be not acceptable for golfer assessment.

HED used a default TTR value of 5% of application rate and a transfer
coefficient of 500 cm2/h to assess the golfer risk   This risk is
presented in Table one.  For the golfers the target MOE is 1000.   

Table 1: Golfers assessment Using Residential SOP default values in
November 2004 

Activity	Application Rate (lb ai/acre)	TTR 

5% of application rate	Transfer Coefficient (cm2/hr) 	Dermal Dose
(mg/kg/day) 	 MOE

       (day 0)

golf course reentry: adult	32.67	18.3	500	0.523	575

	43.57	24.4	500	0.698	430



HED and SRRD met with registrant (S Korpalski of Chemtura) on June 23,
2005. HED  agreed to use the golfer maintenance study which was being
done by Agricultural Re-entry Task Force (ARTF).  HED agreed to use the
transfer coefficients from golf course maintenance workers for golfers
which is by far a conservative estimate. The newly submitted ARTF data
would also enables us to use the TTR study (MRID# 44687101) which shows
a transferability of less than 1%.

Revised Golfer Assessment

A study titled “Determination of Dermal and Inhalation Exposure to
Reentry Workers During Maintenance Activities in Golf Courses” (MRID#
467340-01;) was submitted to the agency by Agricultural Re-entry Task
Force (ARTF). The purpose of this study was to estimate potential dermal
and inhalation exposures and calculate dermal transfer coefficients
among golf course workers re-entering a treated golf course to perform
various golf course maintenance tasks.  The tasks monitored included cup
changing, greens mowing, greens watering, fairway mowing, irrigation
repair, and miscellaneous grooming.  Two trials were conducted at an
18-hole golf course near Hood River.  The first trial was conducted on
the first nineholes and the second trial was conducted on the back nine
holes. In both trials, each greenway or fairway section was treated once
with Daconil Weather Stik® Flowable Fungicide Turf Care( Turf and
Ornamental Fungicide containing the active ingredient (ai)
chlorothalonil. The soluble concentrate product was applied using
commercial ground boom sprayers at a rate of approximately 5.5 lb ai/A.
The application for the second trial took place two days after the
application for the first trial. Exposures were monitored for each
activity on one and two days after application. The potential dermal
exposures were assessed by using whole-body dosimetry (inner and outer),
hand washes, and face/neck wipes.  The potential inhalation exposures
were assessed by using personal air sampling pumps attached to OVS
tubes.  A total of three to four replicates per re-entry interval
(trials 1 and 2 combined) were collected.  For each replicate, the work
period was approximately 1.5 to 4.5 hours long.

Transfer coefficients for potential and total dermal exposure were
calculated .  

  

Dermal transfer coefficients in cm2/hr were calculated by dividing the
corrected residue value (μg) by the replicate duration (hr) and by the
worker-specific turf transferable residue value (μg/cm2). The
maintenance tasks were combined because many of the tasks may be
performed by most of the workers. 

Activity

	Arithamtic Mean	Geometric Mean

Cup Changing	1,311	547

Greens Mowing	847	309

Greens Watering	3,291	1,390

Fairways Mowing	791	588

Miscellaneous Grooming	3,860	1,140

Irrigation Repair	10,534	1,750

All Tasks Combined	3,517	810



HED substituted the combined transfer coefficient from golf course
maintenance study for golfers.  This value (Arithmetic mean 3500 cm2/h)
is used since there is no chemical specific transfer coefficient for
golfers playing on golf courses treated for PCNB, and is considered to
be very conservative.  The risk for golfers is presented in Table 2.  

Table2: Golfer Risk, Using the  Golf Course Maintenance Study Data (MRID
#467340-01) 

Activity	Application Rate (lb ai/acre)	TTR 

ug/cm2	Transfer Coefficient (cm2/hr) 	Dermal Dose (mg/kg/day) 	 MOE

(day 0)

golf course reentry: adult	32.67	0.366	3500	0.073	4100

	43.57	0.488	3500	0.098	3100



The risk estimates for golfers using data from golfer maintenance study
shows MOE’s  > 1000 which are not a concern.

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