# Cholinesterase Monitoring
of Pesticide Handlers in Agriculture Report to the Legislature

As required by RCW 49.17.288

J ANUARY 

# 2007Cholinesterase Monitoring in Agriculture Page 2 of 21 January 2007



### Executive Summary

This report is prepared, as required by RCW 49.17.288, to reflect the firs t three years (2004-06) of implementation of the cholinesterase mon itoring rule, WAC 296-307-148, (the rule) adopted by the Department of Labor and Industries (L&I) in late 2003. 1 Since the experiences of the first two years have previously been docum ented and reported to the legislature 2 this report will focus primarily on the data analysis presented in the 2006 Cholinesterase Scientific Advisory Committee Report to L&I. In some cases, data presented in the 2004 and 2005 reports to the legislature are repeated. 3

During the 2006 agriculture pe sticide application season, 244 employers and 1889 pesticide handlers participated in baseli ne (pre-exposure) cholinestera se testing. Four hundred and seventy one of these pesticide handlers were te sted at least once duri ng the application season (periodic testing). Of these 471 ha ndlers, 50 (10.6 percent) received at least one test with a 20 percent or greater depression in cholinesterase activity requiring the employer to evaluate pesticide handling practices, and 7 (1.5 percent) were temporarily removed from exposure to cholinesterase-inhibiting pesticides because of a more significant cholinesterase depression.

The number of handlers undergoing cholinesterase testing in 2006 was significantly less than in previous years. This is thought to reflect indus try pesticide use patterns, employer experience in identifying employees covered by the testing re quirements of the rule, and employer actions resulting in limiting handler exposure (e.g., product substituti on, spreading pesticide handling duties among employees). Even though fewer ha ndlers underwent periodic testing in 2006 (471) than 2005 (611) the number of handlers experien cing a significant cholinesterase depression remained stable (2005=59, 2006=57).

As in 2004 and 2005, agriculture pesticide handlers with significantly depressed cholinesterase levels were generally employed in the tree fru it industry with operations located in L&I Region 5 ( West Adams, Benton, Chelan, Columbia, Douglas, Franklin, Grant, Kittitas, Okanogan, Walla Walla
and Yakima counties). Airblast pesticide application was mo st often implicated in significant cholinesterase depressions. Toxi city class I and II cholinestera se inhibiting pesticides most frequently handled prior to te sting include ch lorpyrifos, azinphos-methyl, phosmet, formetanate hydrochloride, and carbaryl.

Procedures and requirements for the collecti on of blood samples did not change from the 2005 season. The Washington State Public Health La boratory continued as the only laboratory approved to provide cholinesterase-testing serv ices. Testing was conducted in accordance with the laboratory Standard Operating Procedures (S OP) established in 2005. All test samples were

tested within the time frames established in the SOP. In its analysis of testing services, the Cholinesterase Scientific Advisory Committee conc luded that testing conti nued to be well within acceptable parameters.

As planned during the initial rulemaking process laboratory testing services will shift to the commercial sector beginning in 2007. L&I has selected Pathology Associates Medical Laboratories, Spokane WA, as the single approv ed laboratory to provide testing and data management services under the ru le. Approval of a single laborato ry to provide all testing will serve to eliminate test variability between laboratories.

1 Rulemaking was initiated pursuant to Juan Rios and Juan Farias v. Washington Department of Labor & Industries, et al., 145 Wn.2d 483, 39 P.3d 961 (2002).

2 Cholinesterase Monitoring of Pesticide Handlers in Agriculture: Report to the Legislature (2004 and 2005)

3 The Scientific Advisory Committee for Cholinesterase Monitoring: Report to L&I (2004, 2005, and 2006)Cholinesterase Monitoring in Agriculture Page 3 of 21 January 2007

C HOLINESTERASE M ONITORING IN A GRICULTURE

WAC 296-307-148

W ASHINGTON S TATE D EPARTMENT OF L ABOR AND I NDUSTRIES January, 2006

C ONTENTS

Executive Summary .............................................................................................................. ................2
Background ..................................................................................................................... ......................4
Laboratory Program..............................................................................................6
Summary of 2006 Medical Monitoring Experience ..........................................................................7
L&I Consultation and Compliance Activities ................................................................................10 2007 Program Highlights..............................................................................13 Cholinesterase Monitoring Advisory Committees...............................................15

Appendix Scientific Adviso ry Committee Recommendations...............................17Cholinesterase Monitoring in Agriculture Page 4 of 21 January 2007



### Background

WAC 296-307-148, Cholinesterase (ChE) Monitoring (the rule) was adopted in December 2003. The rule requires agriculture employers to 1) record hours employees handle 4 toxicity class I and II organophosphate and N-meth yl-carbamate pesticides, 2) provide cholinesterase blood testing to employees who handle covered pesticides for 30 or mo re hours in any consecutive 30 day period, and 3) take specified actions when an employee experiences a cholinesterase depression of >20% from their individual baseline. 5 RCW 49.17.288 directs the Washington State Department of Labor & Indus tries (L&I) to submit reports of the results of data collection, correlation, and analysis rela ted to cholinesterase monitoring to th e legislature. This is the third and final of these reports.

Detailed discussions of occupati onal cholinesterase monitoring and history of the rule can be

found in the 2004 Cholinesterase Monitoring of Pesticide Handlers in Agriculture Report to the Legislature, and the Washington State Cholinesterase Testing: Guidelines for Health Care

Providers Manual ( http://www.lni.wa.gov/Safety/Topics/A toZ/Cholinestera se/default.asp ).

In 2006 the Washington State Public Health La boratory (PHL) conti nued to be the sole laboratory approved by L&I to pr ovide cholinesterase-testing se rvices. Blood sample collection and laboratory testing procedur es remained unchanged from 2005. 6 Analysis of Laboratory performance conducted by the Cholinesterase Mo nitoring Scientific Advisory Committee (SAC) concluded that laboratory performance remained well within acceptable limits. 7

Test data continued to be co llected and managed by the PHL a nd Department of Health NonInfectious Conditions Epidemiology program (DOH). DOH maintains the Cholinesterase Monitoring Data System (CMDS), notifies L&I of cholinesterase depressions exceeding 20

percent 8 , and provides a variety of data reports. .

Due to stakeholder concerns regarding employee access to health care provider recommendations the following amendments to the cholinesterase monitoring rule were adopted

for 2006:

The employer must:

• Provide a completed CHOLINESTERASE MONITORING HANDLING HOURS REPORT (F413-065-000) to the physician or other licen sed health care professional (LHCP) for each employee receiving a periodic c holinesterase blood test and make sure the report is submitted to the l aboratory with each periodic cholinesterase test.

• Obtain a written recommendation from th e health care provider for each employee’s blood test and evaluation (including baseline tests) and make sure that the employee receives a copy of the health care provider’s written recommendation

within 5 busin ess days after receipt.

4 Pesticide handling is defined in WAC 296-307-11005

5 Employer requirements for response to significant cholinesterase depression are found in WAC 296-307-14825

6 Standard Operating Procedures for the Determination of Red Blood Cell an d Serum Cholinesterase (2005)

7 The Scientific Advisory Committee for Cholinesterase Monitoring: Report to L&I (2006)

8 Bodies such as the World Health Organization, American Conference of Governmental Hygienists, and the state of

California have identified a 20% decrea se in cholinesterase activity as indicative of pesticide overexposure.Cholinesterase Monitoring in Agriculture Page 5 of 21 January 2007

• Instruct the health care provider to not reveal in writing or in any other communication with you any findings or diagnoses un related to occupational exposure.

• Make sure that any employee declining partic ipation in the cholinesterase testing program receives a copy of the signed dec lination statement within 5 business days after receipt.

The legislature has authorized annual expend itures of up to 1.6 million dollars from the L&I Accident Fund to cover the costs of laboratory testing, and to reimburse employers for other

clinical and related administ rative costs incurred. Employe r reimbursement policies and protocols a can be found at http://www.lni.wa.gov/Safety/Topics/A toZ/Cholinesterase/files/413062af.pdf . Testing, data collection, and employer reimbursement co sts for calendar year 2006 totaled ~$253,170.00.Cholinesterase Monitoring in Agriculture Page 6 of 21 January 2007



### Laboratory program

The PHL continued to provide exemplary servic es in 2006. The addition of a laboratory technician 3, provided by L&I, bolstered resources dedicated to the program.

Both internal and external (blind sample submis sions) quality control progr ams were utilized to monitor testing competency. Cholinesterase Scie ntific Advisory Committee (SAC) analysis of quality control data showed good agreement between internal and external QC data, demonstrating a lack of bias in internal laboratory measurements

. A detailed discussion of laboratory data quality can be f ound in the 2006 SAC report to L&I ( http://www.lni.wa.gov/Safety/Topics/A toZ/Cholinesterase/default.asp).

As planned, and as consistent with medical su rveillance programs required by other DOSH rules, the PHL will no longer be providing testing services and testing will move to the commercial

sector in 2007. L&I has worked with interest ed private laboratories to identify a single laboratory to provide testing se rvices beginning in 2007. Use of a single laboratory serves to eliminate test variability between laboratories.

Laboratory evaluation criteria included;

• Licensure under the Washington State Laboratory Quality Assurance Office

or the Clinical labor atory Improvements ACT (CLIA).

• Ability to perform red blood cell ( acetylcholinesterase) and serum (butyrylcholinesterase) cholinesterase testing utilizing the Ellman Method. Test protocols must be reviewed and a pproved by the Washington State Public Health Laboratory.

• Demonstration of a robust quality assurance program including, but not limited to;

 Participation in the College of American Pathologists cholinesterase

proficiency testing program

 Submission of a quality assurance pl an with approval by the Public

Health Laboratory

 Routine review of quality assuranc e data by the Public Health

Laboratory.

• Ability to report test results within 5 days of sample collection.

• Maintenance of test results and rela ted demographic information in an Aggregate electronic data base with transf er of surveillance data to L&I on a

scheduled basis.

L&I has chosen Pathology Associates Medical Laboratories (PAML), Spokane WA, to provide all testing services beginning January 15, 2007. Ongoing approval will be dependent of factors including 1) demonstrated labor atory capacity to manage and pr ocess samples as dictated by standard operating procedures, 2) maintenance of formalized QC programs, 3) competency of data management systems, and 4) customer service programs.Cholinesterase Monitoring in Agriculture Page 7 of 21 January 2007



### Summary of the 2006 Medical Monitoring Experience

As in 2004 and 2005 the vast majority of employe rs participating in the medical monitoring program had operations located in L&I Regi on 5 (West Adams, Benton, Chelan, Columbia, Douglas, Franklin, Grant, Kittitas, Okanogan, Wa lla Walla and Yakima counties.) L&I Regions 1 (Island, San Juan, Skagit, Snohomish, and Whatcom) and 4 (Clark, Cowlitz, Grays Harbor,
Klickitat, Lewis, Mason, Pacific, Skamania, Thur ston and Wahkiakum) accounted for the remainder of the samples submitted

Table 1. Monthly blood samples submitted 2004-06 (2006 SAC report)

Time Period Number of Samples Per Month & Year

Month 2004 2005 2006 January 22 74 22 February 1039 1127 239

March 1338 1376 1076 April 459 144 612 May 331 97 296

June 105 35 257 July 75 23 80 August 40 70 * Total Blood Samples 3409 2946 2582 * 2006 analysis included data collected from January through July

During the 2006 pesticide application season, 244 employers and 1889 employees submitted

cholinesterase baseline tests. The number of samples submitted to the lab from January through July totaled 2582 (Table 4.1) The total number of samples decreased 12-13% each year of the program, presumably (at least in most cases) because their exposure levels remained below 30 hours in any one 30-day period and employer actions resulting in d ecreased use of cholinesterase inhibiting pesticides.

Of the 471 employees who receiv ed at least one periodic te st, 50 employees (10.6 percent) received at least one periodic te st result with a 20 percent or greater cholinesterase depression, requiring the employer to evaluate pesticide ha ndling practices for possible deficiencies. Of those same 471 employees, 7 (1.5 per cent) were temporarily removed 9 from exposure due to a more significant depression (at least 30 pe rcent depression in red blood cell [RBC] cholinesterase or at least 40 pe rcent depression in serum cholines terase (Table 2.). The 57 total employees who experienced a significant cho linesterase depression in 2006 worked for 30 different employers. Only two employees experi enced an RBC ChE depression with one of these

9 Employees may return to handling covered pesticides when c holinesterase levels return to within 20% of baseline. While medically removed from exposure to covered pestic ides employee pay, seniority and other benefits are maintained at the pesticide handler level for a maximum of 3 months.Cholinesterase Monitoring in Agriculture Page 8 of 21 January 2007

employees experiencing both an RBC and seru m ChE depression. No employees were identified, through the monitoring program, with symptomatic pesticide illness.

Table 2. Comparison of employer and employ ee cholinesterase testing and significant cholinesterase depressions in 2004-06

2004 2005 2006

Employers participating in testing 380 316 244

Employees submitting

baseline tests 2630 2263 1889

Employees with at least 1 periodic test 580 611 471

Periodic tests 911 970 692

Employees with ChE

depression to work

evaluation level 97 (16.7%) 49 (8.0%) 50 (10.6%)

Employees with ChE depression to exposure

removal level 22 (3.8%) 10 (1.6%) 7 (1.5%)

In adopting RCW 49.17.285, the Legi slature required employers to submit pesticide handling hours to L&I on each employee who received a peri odic test. The SAC analyzed handling hours in relation to change in cholinesterase leve ls. No significant relationship was found for RBC cholinesterase. A small relationship was found fo r serum cholinesterase. The current 30 hour exposure threshold will remain in place in light of the SAC finding no conclusive evidence supporting a change.

The rule allows covered pesticid e handlers to decline participation in the testing program. The 2003 Agriculture Cholinesterase Mon itoring Cost Benefit Determination ( http://www.lni.wa.gov/wisha/p-ts /Cholinesterase/ChE-BCD-Final.pdf ) estimated that the declination rate would be approximately 15%. In an attempt to assess the proportion of handlers offered participation in the program but declin ing testing from the health care provider, L&I surveyed the five health care c linics performing the majority of baseline cholinesterase tests. Each clinic was asked how many handlers were referred to the c linic and of those, how many declined participation. A ll clinics had a less than 15% declina tion rate, well within the expected rates (Table 3.). There are no comparable data for 2004.Cholinesterase Monitoring in Agriculture Page 9 of 21 January 2007

Table 3. Declination rates at th e five clinics providing the mo st baseline cholinesterase blood samples. (2006 SAC report)

Provider Baselines Declinations Declination Rate

2005 2006 2005 2006 2005* 2006

1 559 576 65 89 10.4 13.4

2 117 87 1 5 >0.1 5.4

3 73 118 10 34 12.0 22.3

4 106 61 14 5 11.7 7.6

5 701 623 120 51 14.6 7.6

Total 1556 1465 210 184 11.9 11.2

The rule allows employees to either choose to participate or declin e participation in the employer’s cholinesterase testing program. The option is consistent with other WISHA rules that contain medical surveillance provisions. As an additional protection against potential coercion regarding the employee’s decision to part icipate in the program the rule includes the requirement that this decision is made in convers ation with the health car e provider. There have been no cases of potential coer cion identified. L&I believes th at adding additional employer requirements and dedicating progra m resources to track employee de clinations is not justified.Cholinesterase Monitoring in Agriculture Page 10 of 21 January 2007



### L&I Consultation and Compliance Activities

In 2006, L&I transitioned to use of standard consultation and compliance programs in response to significant cholinesterase depressions (C hE depression >20% fr om baseline). WISHA Regional Directive 33.27, C holinesterase Depression (http://www.lni.wa.gov/Safety/R ules/Policies/PDFs/WRD3327.pdf ), provides consistent enforcement policy. Employers with employees who experienced signif icant cholinesterase depressions were contacted and offered field consultation servi ces. Compliance referrals are made under the following circumstances:

• The employer declines the offer of c onsultation services for a second time.

• An employer has received at least 2 consu ltations as a result of cholinesterase depressions but continues to have ad ditional employees with a significant cholinesterase depression.

• Consultation identifies circumstances that warrant a compliance referral, e.g. hazards are not abated in a timely manner.

• DOSH Technical Services identifies tre nds or circumstances that indicate employer safety program deficiencies, e .g. cholinesterase depression clusters or ongoing employee cholin esterase depressions.

The ChE field consultations and enforcement i nvestigations were performed by one of five DOSH consultation and compliance staff. DOSH c onsultants collected surveillance information using a standard series of questions (see WR D 33.27). The questions in cluded worker name, birth date, primary language and number of year s as a handler. The employer name was recorded along with additional information regarding the number of acres, crop types, the types of ChE inhibiting pesticides handled, the number of ha ndling hours, handler trai ning, types of pesticide handling activities, use of personal protective equipment (PPE), decontamination facilities, handler symptom history, and identification of the potential cause of exposure. The investigator summarized the reports for use by the scientific advisory committee. Employers who received a ChE consultation or compliance inspection from DOSH are required by stat e law to correct any serious job safety and health hazards or deficiencies found.

Twenty-one of the 30 employers who had employees with ChE depression received consultation visits. Two additional employers received complianc e visits due to having multiple workers with depressed cholinesterase levels.

The vast majority of consultations revealed that over-exposures o ccurred in tree fruit operations. There was one employee working in a field crop operation (onions, beets, green beans, grass seed) applying pesticides to the ground from tr actor mounted spray booms. Air blast application of the covered pesticides may not be the sole contributing exposure factor for the workers with depressed cholinesterase levels. Other e xposure hazards found include not properly decontaminating before meal or bathroom breaks and not wearing appropriate personal protective equipment, e.g., the use of leather boots when the pestic ide label required the use of protective footwear.Cholinesterase Monitoring in Agriculture Page 11 of 21 January 2007

Common rule violations found duri ng consultation visits include:

• WAC 296-307-6005 – Develop and maintain wr itten respiratory protection program.

• WAC 296-307-13050 – Provide decontamination s upplies (e.g. water, soap, disposable hand towels, and an emergency change of clothing).

• WAC 296-307-13025 – Provide effectiv e pesticide safety training.

• WAC 296-307-60805 – Provide eff ective training on the use and maintenance of respirators.

• WAC 296-307-13045(3)(f) – Ensure use of appr opriate personal protective equipment

• WAC 296-307-14835 – Conduct and document work practice evaluations of employees experiencing significant ChE depression.

Potential exposure routes identified during consultation visits include:

• Cotton ball cap (bill exposed) worn under protective head gear

• Lack of chemical resistant footwear

• Improper maintenance and storage of respirators

• Improper decontamination of personal prot ective equipment, incl. respirators

• Exposure to contaminated equipment

• Overuse of respirator cartridges

• Use of cotton gloves under rubber gloves,

Two employers were referred for compliance investig ations. Both employers had clusters of five employees with cholinesterase depressions gr eater than 20% from ba seline. In the first compliance investigation, the em ployer was cited for two serious violations: 1) not ensuring handlers’ head gear (hats) were chemical resi stant and 2) not ensuring emergency eyewash was available on every tractor used to spray pesticid es. There were no serious violations found on the second compliance investigation. However, the compliance officer noted potential exposure routes: 1) not washing hands before and after using the ba throom, 2) wearing hooded cotton sweat shirts under rain gear, and 3) not showering or changing cl othes after applying pesticides.

In addition to the compliance investigations, L&I conducted scheduled investigations with a group of employers who had participated in the ChE monitoring program in 2005 but had not participated in the program in 2006. One hundred twenty-four employers were identified and thirty-one (~25%) were chosen to receive a comp liance visit. A focus of the inspection was to determine compliance with the cholinesterase m onitoring rule. Based on a review of handling records by DOSH compliance inspector s all of the inspected employers were in compliance with the ChE monitoring rule. Employers made the foll owing engineering or ad ministrative controls to mitigate worker exposure to covered pesticides:Cholinesterase Monitoring in Agriculture Page 12 of 21 January 2007

• The owner applied the covered pesticides.

• The employer eliminated the use of cholinesterase-inhibiting pesticides.

• The farm was converted to organic farming.

• The employer hired additional pesticide applicators to decrease the number of exposure hours.

• The employer monitored and restricted handling hours to keep workers under the

30 hour threshold.

• The employer switched from Guth ion to Assail for coddling moth.

• The employer increased spray rate per acre to limit exposure time.

• The employer increased use of integr ated pest management techniques.

The majority of significant cholinesterase depr essions occurred during th e beginning of the tree fruit application season (dormant season spraying). Later depressi ons tended to coincide with orchard activities such as application of fr uit thinning and post bloom cover sprays. During dormant season spraying, the orga nophosphate insect icide Lorsban (chlorpyrifos) is used. The fact that the majority of significant cholinestera se depressions were due to depression of serum

cholinesterase is consistent with the use of chlor pyrifos as it has an affinity to bind with serum

cholinesterase. Other cholineste rase inhibiting pesticides hand led by these employees include Guthion (azinphos-methyl), Carzol TM (formetanate hydrochloride), Imidan TM (phosmet.), and Sevin (Carbaryl).Cholinesterase Monitoring in Agriculture Page 13 of 21 January 2007



### 2007 Program Highlights

The 2004-06 experience has demonstrated the feasibility of a state wide occupational cholinesterase monitoring program. The rule has provided clear direction and support to employers, employees, and health care provide rs. The cholinesterase monitoring program continues to demonstrate improve d function and has reached a leve l of self sustaining maturity. The Cholinesterase Monitoring Benefit-Cost Determination listed the following probable benefits of a cholinesterase monitoring rule:

• Greater certainty about the fre quency of pesticide overexposure

• Avoidance of serious pesticide illness

• Improved compliance with the pestic ide worker protection standard

• Identification of any existing PPE, work pract ice and engineering control requirements that are not sufficient to protect pesticide handlers from exposure

• Greater awareness of chemical and exposure hazards

The information gathered over the last three ye ars has shown that thes e benefits are being

realized. There is an increased awareness in the agriculture indus try of the hazards inherent in pesticide handling, causes of ove rexposure are being identifie d, handler pesticide training programs have been bolstered and educatio nal opportunities expande d, and laboratory blood cholinesterase testing has shown itself to be an effective method to iden tify overexposure prior to the onset of illness. While much data has not been available to allow for precise quantification of benefits it is apparent th at the goals of increased knowle dge and improved worker health protection have and are being achieved.

The rule functioned well in 2006 and is quickly m oving to a level of self sustaining maturity. No immediate rule or enforcement policy changes are immediately anticipated for 2007. While the rule will remain intact, program changes that will occur are:

• Laboratory services will tr ansition from the Public H ealth Laboratory to Pathology Associates Medical Laboratories (PAML). The transition to the private sector was anticipated and is consistent with the provision of medical su rveillance services contained in other rules, e.g. lead, cad mium. All employer testing costs will continue to be reimbursed through existing structures.

• In previous years L&I often had knowledge of test results prior to the health care provider. Due to this situation L&I el ected to notify the health care provider by telephone of all significant cholinesterase depr essions. In 2007 all test results will be reported electronically (web based, fax) by the laboratory to the health care provider eliminating the need for telephone reporting.Cholinesterase Monitoring in Agriculture Page 14 of 21 January 2007

• Laboratory surveillance and data management will begin transitioning from the Department of Health (DOH) to PAML. In order to ensure that appropriate data management systems are in place DOH will continue to operate the Cholinesterase Monitoring Data System (CMDS) through 2007 and in parallel with PAML. CMDS will be operated out of the DOH Office of Environm ental Assessments Pesticide Program.

L&I will continue to collect and manage laboratory test and field surveillance data gathered during consultation and compliance activities. This data will be available for analysis and used to direct rule and related program improvements.

At the time of this writing L&I has not had sufficient time to thoroughly consider the recommendations provided in the 2006 SAC report (Appendix). While many of the recommendations are specifically provided for long term considera tion it may be practical to

take more immediate action on some recommen dations. L&I will continue to work with

stakeholders in order to make these determinations

.

Any questions or requests for additional information should be directed to:

John Furman Industrial Hygiene Services Manager Department of Labor & Industries Division of Occupational Safety & Health

360-902-5666 Furk235@lni.wa.govCholinesterase Monitoring in Agriculture Page 15 of 21 January 2007



### Cholinesterase Advi sory Committees

Scientific Advisory Committee

• Dave Bonauto, MD, Associate Medical Dir ector of the Department of Labor and Industries, Safety and Health Assessmen t for Research and Prevention Program

• Rupali Das, MD, MPH, California De partment of Health Services

• Allan Felsot, PhD, Washington State University Extension Specialist and Environmental Toxicologist

• Matthew C. Keifer, MD, MPH, Associate Pr ofessor of Environmental and Occupational Health Sciences, University of Washington

• Michael O’Malley, MD, MPH, Staff Physician with UC Davis Employee Health Services and consultant to the California Department of Pesticide Regulation' s Worker Health and Safety Branch

• Juliet VanEenwyk, PhD, State Epidemiol ogist for Non-Infectious Conditions, Washington State Department of Health

• Gerald van Belle, PhD, Professor of Biosta tistics and Environmental and Occupational Health Sciences, University of Washington

• Barry Wilson, PhD, of the Department of Environmental Toxicology at the University of California, Davis

Stakeholder Advisory Committee

Allan Felsot, PhD Professor & Extension Specialist, Entomology/Environmental Toxicology, Washington State University

Jim Jesernig Attorney, Wash ington state potato growers

Matthew Kiefer, MD, MPH, Associate Professo r, Depts. of Medicine & Environmental & Occupational Health Sciences , University of Washington

Nathan Lacy, PhD, Office Director fo r Environmental Laboratory Services, Washington State Public Health Laboratory

Evi Licona, Columbia Legal Services

Kirk Mayer, Washington Growers’ Clearing HouseCholinesterase Monitoring in Agriculture Page 16 of 21 January 2007

Erik Nicholson, United Farm Workers

Dorothy Tibbetts Manager, Office of Pesticide Investigation and Survei llance, WA State Dept.

of Health

Ann Wick Washington State Dept. of Agriculture, Pesticide Management

L&I appreciates the work of the Scientific Advisory and Stakeholder Committees and thanks their respective employers for making them availa ble to assist in evaluating the rule and its implementation.Cholinesterase Monitoring in Agriculture Page 17 of 21 January 2007



### APPENDIX

2006 Cholinesterase Scie ntific Advisory Comm ittee Recommendations

The following recommendations are contained in the 2006 Scientific Advisory Committee Report to the Department of Labor & Industries http://www.lni.wa.gov/Safety/Topics/AtoZ/C holinesterase/files/2004-06ChESACreport.pdf

General recommendations for program improvement

1 . Continue retrospective evaluation of program results, and consider future changes to the

rule. The SAC feels that there would be scientific merit in narrowing the scope of the rule, at a point when it could be establis hed that the current rule include s handlers for whom the risk of significant cholinesterase depres sion is categorically less than for the handler population as a whole. This will require expanded data coll ection and ongoing review of program results.

2. Continue central data collection for the life of the program. The SAC suggests strongly that a centralized data collection system similar to CMDS continue and DOSH analyze these data annually and compare them across years. Sufficient resources need to be assigned to the program to assure that data quality is consistent and that important trends in cholinesterase depressions are iden tified and appropriate responses taken.

3. Collect additional data with each periodic test . Continued collection of handling hours might be useful if other information rega rding workplace conditi ons and practices was also collected for each handler. Examples of additional questions might include type of crop, product applied, method of application. Th is would be important for considering rule changes based on patterns of exposure by any of these factors. Absent this additional detail, it is doubtful if compiling handling hours as a routine feat ure of the monitoring program is justified, so long as thos e data are maintained by each employer

.

4. Establish a provider certification or other provider quality assurance program . The

SAC believes that role of the health care provider and clinic staff in informing the handler about the program, in obtaining me dical and related information from the handler, and in interpreting ChE values is cri tical to the quality of the program. There is an ongoing need to provide training and update information to the staff that actually counsel handlers and carry out other monitoring program functions. The SAC recommends that L&I develop a mechanism for assuring quality in this role, particularly as medical and clinic personnel change, and as the program moves from a start-up phase with relatively close oversight to an ongoi ng program. Ideally, each handler would have a designated health care provide r who would be certified by L& I and would participate in annual training. In addition to provider certif ication, L&I should develop a system to certify participating clinics. The certification programs n eed to pay ongoing attention to the training and guidance materials on how to conduct cholinesterase monitoring. Periodic or ongoing web based training opportuniti es could be made available and should be a requirement for participation for new and continuing clinic participants. These should be periodically updated based on in formation obtained through the systematic reviews of monitoring program results, field consultations or insp ections, and throughCholinesterase Monitoring in Agriculture Page 18 of 21 January 2007

consultation with national expert s and the participating clinics. These updates should incorporate advances in communication and laboratory tech nology. This activity could be assigned to the

Office of the Medical Director of L&I or could be a shared responsibility between DOHS and the University of Washington O ccupational Medicine Program.

5. Maintain Laboratory Services. In 2004 and 2005, the SAC expressed concern that changing the laboratory or moving to multiple labs providing monitoring services would threaten the validity and comparability of the test data. Given the high degree of acceptance, and objective measures of reliability demonstrated in 2004-2006, purely

technical considerations would i ndicate that the safest course would be to continue to use the PHL for program support. At this writing, there is active procurement to identify a commercial laboratory to replace the Public Health Lab as the provider of testing

services. SAC reasserts the scientific valu e of having a single lab of known quality supporting this program. The transition to a new lab carries inherent risks: data quality and user confidence in it may suffer as a tran sitional effect, or might fail to be adequate for multiple years. This would not only risk increasing the number of false negative results (leaving handlers unprot ected) and/or false positiv e results (wasting state and employer resources), but could affect overall pr ogram sustainability if participation rates are then affected. Specific recommendations for how risks might be minimized in this

transition are offered in the next section.

6. Continue active L&I Consultation Services fo llow-up with employers when there are ChE depression alerts . The SAC recommends that ther e be a response time goal set for

consultation field visits before the start of each monitoring season, and that this be kept as short as is practical (bearing in mind that as little as 9.5 days was demonstrated to be achievable in 2005 for response to exposure removal alerts, but also that employer scheduling constraints affect this). Additio nally, the SAC recommends that L&I clearly

communicate the roles of consultation and compliance groups when there are repeated ChE depressions for a handler or multiple ChE depressions for handlers at a single

grower.

7. Develop new or better methods for dissemina ting information on exposure reduction

. The SAC encourages L&I to develop systems that allow for timely sharing of information gathered during field activities in cluding consultation or compliance visits in order to communicate new findings within a growing season to the various state agencies and other groups that are involved in conducting and de veloping farm worker and agricultural employer training, outreach and pesticide license testing related to agricultural pesticide use. This system would likely be more effective if it could be operated jointly with other groups involved in agricultural worker safety issues.

8. Continue to assess program performance and impact. Systematic review of the program should include an assessment of the participating clinic practices, satisfact ion surveys of handlers and employers, review of quality assurance pr actices of the participating laboratory or laboratories, response time for no tification of depressi ons, the nature of employee response to notifications of depressions and e ffect of the cholinesterase monitoring rule on chemical choices, and handler assignments. Although this program is becoming more established and routine, there are several important aspects of it th at are as yet poorly understood or need continued tracking. These include:Cholinesterase Monitoring in Agriculture Page 19 of 21 January 2007

Effectiveness of educa tional outreach efforts (for providers, handlers, and employers ). This includes efforts to inform program par ticipants about changes in program aspects, providing basic information about the program to new participants, and ongoing efforts to educate employers and handlers regarding the exposure risks.

Handler perception

. As the handlers are the primary bene ficiaries of this program, their continued participation and t hus satisfaction with the pr ogram should be assessed and optimized. The SAC cannot determine why some handlers decline to participate in the program. This information could be important for assessing how employers and providers present the program, how handl ers perceive the program, and the effectiveness of educational outreach efforts (t o growers, pesticide handlers, and to health care provider groups). Given that the population presently participating is largely Hispanic, many of who speak English as a second language, particular attenti on needs to be paid to the understanding that this population has of the potential benefits of this program.

In addition

, a related (research) questi on that has not been ev aluated under the present system is the effect of the program on the atti tude of handlers toward the risks they face in handling covered pesticides. The initiation of a medical test in response to a handler exposure emphasizes the importance of this exposure to the handler and the employer. The effect on knowledge, attitudes, and beha viors of handlers and employer due to the existence of this program is a dimension of program that would be valuable to understand and describe for the benefit of future such programs.

Employer participation

. The SAC recommends that complia nce investigations (checking “drop-out” employers or other spot checks of employer compliance) as an active part of the overall cholinesterase monitoring program be continued. Active investigation of other agricultural operations not curr ently under the rule which us e organophosphate and N-methylcarbamate pesticides might also be considered

Handler notification of routine results

. The failure of handlers to get their results back in a timely way could be a significant disincentiv e for future participation. The SAC as well as Stakeholders unanimously support timely fee dback to handlers, even for results that do not indicate overexposure to pe sticides. Currently, the empl oyer is required by L&I to provide timely interpretation of tests to each handler. Routine assessment of this aspect of employer compliance with the rule is n eeded. This could be added as a question on each periodic blood draw (e.g., “Have you been notified of your results from the prior month?”). The establishment of a central cal l in number and a unique identifier provided

to the handler is another wa y to resolve this problem.

9. Support the research value of the monitoring program. The opportunity to recognize common factors leading to pest icide overexposure and cholinesterase depression has not been realized as yet. New understanding of the underl ying causes of exposure or failures of protective measures are not likely to arise from routine monitoring effort per se, but can benefit from monitoring activities and data. The SAC recognizes that resear ch is not the primary objective of ChE monitoring, and that L&I / DOSH are regulatory programs . The SAC recommends that research uses of the program by third parties be encouraged by L&I, through cooperation and, where feasible, through selec tive opportunities for research support. Beyond sharing of program data as they currently exist, “c ooperation” might include adopting modified practices to assist research, where such modifications are no t intrusive. SomeCholinesterase Monitoring in Agriculture Page 20 of 21 January 2007

possibilities for how this might be done include:

• The Department could organize and support an annual meeting to allow interested non-L&I groups to obtain and share anal ysis of program results. A related activity would be for Stakeholders to conf er with L&I to identify priority issues where investigation is needed for program assessment or improvement purposes.

• The Department could support (either fi nancially, or by cooperation) periodic studies conducted by third pa rties such as WSU or UW, that explore the causes of cholinesterase depression, the rate of participation among eligible employers and the reasons for non-participation of both handlers and employers. These projects could be in response to solicitations from L&I, or unsolicited research ideas, or

both.

• The SAC feels that L&I shoul d be directive in research that it funds, and that there should be a sign ificant Agency need ju stifying funded projects.

Recommendations for maintaining program quality in 2007

Based on information from L&I, the SAC exp ects that the ChE monitoring program will undergo significant changes for the 2007 gr owing season. Notable potential changes include use of a single commer cial laboratory and decreased involvement of L&I and the DOH in system function. It is unclear whether these changes will impact the effectiveness of the program.

The SAC recommends evaluation of the program for at least one additional year to assess

• Laboratory accuracy and timeliness for running the assay, matching baseline and periodic tests, calcul ating percent depression, and notifying providers.

• Provider timeliness and accuracy in matching baseline and periodic tests, calculating percent depression, and notifying growers and handlers. To accomplish this evaluation, L&I needs access to participant identifiers and test results from the laboratory and from providers.

Manual matching of periodic samples to a single handler continues to require significant

effort and could be a source of error in th e future. As this task is reassigned to a commercial provider, the SAC recommends that L&I and st akeholders consider the feasibility of issuing unique id entifier codes to each handler to be used by the health care provider in collecting and submitting samples.

The SAC has considered the arguments fo r and against continuation of the RBC ChE testing. Arguments against continuing to perfor m this test are that the RBC test does not detect very much exposure and added only one “work practices” al ert in 2006. It is therefore potentially a case of significant cost and effort for little return. The performance on this test is inherently le ss robust than for the serum ChE, and no appropriate control material is available for QC purposes. Arguments for continuing to perform this test are that the marginal savi ngs of dropping this test would be small (an example cited by L&I staff was that private labs would charge $25/sample for one test and $30/sample for both tests); the response of RBC ChE compared to serum ChE could change if the pesticides in use chan ge, and the failing to know about RBC ChE depression is more significant than for serum ChE depression, as the RBC enzyme isCholinesterase Monitoring in Agriculture Page 21 of 21 January 2007

biologically closer to the hea lth effect of concern (depress ion of AChE in the central nervous system). Our recommendation is that L&I determine the cost differential of one test versus both tests as part of its lab selec tion process, and that if the differences are not large, that both tests be continued for the present.

To assure quality of the laboratory tests, th e SAC recommends that L&I, in consultation with stakeholders provides ove rsight of laboratory operations by establishing definitions and processes for which the laboratory can prov ide documentation. These include definitions and processes for assuring:

• Data validity on a batch or submission basis.

• Laboratory capacity to receive sample subm issions at their peak seasonal rates and to complete analyses without exceeding holding times.

• Laboratory ability to store samples at –70°C for up to 6 months in order to respond to any questions aris ing from patterns in results across the monitoring

season.

• Extra-lab quality control testing (operated by L&I or by health care providers under L&I direction) to serve as an adjunct to within-lab QC efforts and capture possible sources of variab ility related to sample collection and shipment.

• Lab certification by external bodies base d on performance testing, such as the College of American Pathologis ts (CAP) program, is an important qualification of the lab providing ChE testing.

• Interlab comparison programs and the development and use of reference or benchmark samples (particu larly for the membrane-bound form of ChE detected in the RBC assay) are highly desirable

An annual audit of lab performance accordi ng to these standards and criteria is recommended. If the audit is conducted by L& I staff, disclosure of the findings and

recommendations to stakehol ders is also recommended.