                 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
                         WASHINGTON, D.C. 20460      

                                                	OFFICE OF CHEMICAL SAFETY AND 
                                                           POLLUTION PREVENTION
	


MEMORANDUM

Date: 	May 25, 2011

SUBJECT:	Metsulfuron: Review of Human Incidents

PC Code: 122010
DP Barcode: D389637
Decision No.: 448313
Registration No.: NA
Petition No.: NA
Regulatory Action: NA
Risk Assessment Type: NA
Case No.: NA
TXR No.: NA
CAS No.: 74223-64-6
MRID No.: NA
40 CFR: NA
		              									Ver.Apr.08
	          	
FROM:	Khin Swe Oo, Environmental Health Scientist
		Toxicology and Epidemiology Branch
		Health Effect Division (7509P)	

THROUGH:	David Miller, Acting Branch Chief
		Toxicology and Epidemiology Branch
		Health Effects Division (7509P)
			
TO: 		Charles W. Smith, Risk Assessor
		Risk Assessment Branch VI
		Health Effects Division (7509P)
			and				
		Jill Bloom, Chemical Review Manager
		Risk Management & Implementation Branch II
		Pesticide Re-evaluation Division (7508P)

I. CONCLUSION 

Based on the low frequency and severity of incident cases, there does not appear to be a concern at this time that would warrant further investigation. The Agency will continue to monitor the incident information and if a concern is triggered, additional analysis will be included in the risk assessment.

II.	ACTION REQUESTED

This review is intended to fulfill our requirement to docket summaries of incident data that were reported to the Agency, as well as to ensure human incident data and the Agricultural Health Study (AHS) are part of the problem formulation phase of registration review. Reports of adverse health effects allegedly due to a specific pesticide exposure (i.e., an "incident") are largely self-reported and therefore, generally speaking, neither exposure to a pesticide or reported symptom (or the connection between the two) is validated.  Typically, causation cannot be determined based on incident data.  However, incident information can be an important source of feedback to the Agency  -  incidents of severe outcome, or a suggested pattern or trend among less severe incidents, can signal the Agency to further investigate a particular chemical or product. Observational epidemiology studies relate the risk of disease, e.g., cancer, and exposure to an agent such as a pesticide product in the general population or specific sub-groups like pesticide applicators. 

III.	BACKGROUND		

For this evaluation, the OPP Incident Data System (IDS) was utilized for pesticide incident data on the active ingredient metsulfuron (PC Code 122010).  The purpose of the database search is to identify potential patterns on the frequency and severity of the health effects attributed to metsulfuron exposure.  The IDS includes reports of alleged human health incidents from various sources, including mandatory Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) Section 6 (a) (2) reports from registrants, other federal and state health and environmental agencies and individual consumers. Since 1992, OPP compiles these reports in IDS.  IDS contain reports from across the U.S. and most incidents have all relevant product information recorded. Reports submitted to the IDS represent anecdotal reports or allegations only, unless otherwise stated in the report.  The AHS is a high quality, prospective epidemiology study evaluating the link between pesticide use and various health outcomes including cancer. The AHS includes private and commercial pesticide applicators and their spouses. If there are AHS findings relevant to a particular pesticide going through registration review, the Agency will ensure they are considered in the problem formulation/scoping phase of the process and, if appropriate, fully reviewed in the risk assessment phase of the process. The AHS includes information on use of 50 different pesticide active ingredients commonly used in agriculture.

IV. RESULTS/DISCUSSION

IDS records incidents resulting in higher severity outcomes in more detail, in a module called the Main IDS module.  This system stores incident data for death, major and moderate incidents, and it includes more details about the location, date and nature of the incident.  Main IDS incidents involving only one pesticide are considered to provide more certain information about the potential effects of exposure from the pesticide.  The less severe human incidents (minor, unknown, or no effects outcomes) are reported by registrants as counts called aggregate summaries and are recorded in a separate module called Aggregate IDS.   

In Aggregate IDS, from January 1, 2006 to March 31, 2011 there are 37 incidents involving metsulfuron.  Because it falls within the categories reported as counts (which includes minor, unknown or no effects), there is no unique report that provides details about the incident and single chemical incidents are not distinguished from multiple chemical incidents; however, a high frequency of incidents indicates there is a high potential for exposure and vice versa.  For metsulfuron, there appears to be a low potential for exposure. 

 For the Main IDS, from January 1, 2006 to March 23, 2011, there are 12 cases reported that involve the active ingredient metsulfuron. However, there is no incident reported for single chemical metsulfuron only in the database.  

Metsulfuron is not included in the AHS, and therefore does not provide information for this report.

Based on the low frequency and severity of incident cases, there does not appear to be a concern at this time that would warrant further investigation. The Agency will continue to monitor the incident information and if a concern is triggered, additional analysis will be included in the risk assessment.


