UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460 OFFICE OF CHEMICAL SAFETY AND POLLUT I ON PREVENTI ON

MEMORANDUM Date: August 20, 2013 SUBJECT: Dimethyl disulfide (DMDS): Tier I Review of Human Incident s PC Code: 029088 DP Barcode: 0413869 Decision No.: 479821 Petition No.: NA Risk Assessment Type: NA TXRNo.:NA MRIDNo.:NA Registration No.: NA Regulatory Action: NA Case No.: NA CAS No.: 624-92-0 40CFR : NA Ver.Apr.08 E li zabeth Evans, Environmental Protection Specialist
.

### ~- {) T oxicology and Epidemio logy Branch

### J-'1~ ..

### ~**~** FROM: Health Effects Division (7509P)**v-·r-~-** 

# · · and Shanna Recore, Industrial Hygienist Toxicology and Epidemiology Branch Health Effect Division (7509P)

# THROUG**avid** M ill er, Acting Branch Chief Toxicology and Epidemiology Branch Health Effects Division (7509P) TO: Shalu Shelat, Risk Assessor Risk Assessment Branch VI Health Effects Division (7509P) and Andrea Moj ica, Chemical Review Manager Risk Management & Implementation Branch 2 Pesticide Re

-evaluation Division (7508P) Summary and Conclusions Based on the low frequency and severity of incident cases reported for, 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.
Page 1 of4Detailed Review 

### I
. 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) i s validated or otherwise confirmed. Typically, causation cannot b e 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 signa l 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 pest ic ide applicators. 

### II. BACKGROUND Dimethyl disulfide (DMDS) is a soil fumigant. 

### It is applied by shank injection, broadcast, or by drip irrigation to raised beds. DMDS applications are made pre-plant to fields that will be used to grow berry (blueberry and strawberry), cucurbit vegetable (cucumber, squash, and melon), fru iting vegetable (tomato, pepper, and eggplant), field-grown ornamental, and forest tree nursery crops . These treatments are intended to control weeds such as nutsedge (purple and yellow), chickweed, lambsquarters, purslane, and grasses; soil-borne plant pathogens such as Verticillium spp., Fusarium spp . , Pythium spp., Sclerotinia spp ., and Rhizoctonia spp.; and nematodes such as Root Knot (Southern, Northern, and Colombian), Stubby Root, L esion, Stunt, and Sting. 1

For this evaluation, both the OPP Incident D ata System (IDS) and the Centers for Disease Control and Prevention/Na tional Institute for Occupational Safety and Health (CDC/NIOSH) Sent inel Event Notification System fo r Occupational Risk-Pesticides (SENSOR) databases were co n sulted for pesticide incident data on the active ingredient DMDS (pc code: 029088). The purpose of the database search i s to identify potential patterns in the frequency and severity of the health effects attributed to DMDS exposure. DMDS i s not included in the AH S, and therefore this study does not provide information for this report. 

### III. RESULTS/DISCUSSION
a. IDS (Incident Data System) OPP's 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

1 Excerpt from t he DMDS Fact She et, found online at: http: //www.epa.gov /pesticides/chem search /reg actions/pending/fs PC-029088 09-Jul-1 O.pdf
Page 2 of4from registrants, other federal and state health and environmental agencies, and individual consumers. Since 1992, OPP has compiled these reports in IDS. IDS contains 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. IDS records incidents in one of two modules: Main IDS and Aggregate IDS:

o Main IDS contains incidents resulting in higher severity outcomes and provides more detail with regard to case specific. This system stores incident data for death, major and moderate incidents, and it includes information 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 ofexposure from the pesticide.

o Aggregate IDS contains incidents resulting in less severe human incidents (minor, unknown, or no effects outcomes). These are reported by registrants only as counts in what are aggregate summaries. For the Main IDS, from January 1, 2008 to June 11, 2013, there was 1 incident reported for single chemical only in the database. This incident was classified as moderate severity. There were 2 additional incidents reported involving more than one chemical. These incidents were classified as minor severity. Overall, there are few incidents involving DMDS reported to IDS. In Aggregate IDS, from January 1, 2008 to February 19, 2013, there were 0 reported incidents involving DMDS. 

### b. SENSOR-Pesticides The SENSOR-Pesticides database covers 11 states from 1998-2009, although reporting varies from state to state. Cases of pesticide-related illnesses are ascertained from a variety of sources, including: reports from local Poison Control Centers , state Department of Labor workers' compensation claims when reported by physicians, reports from Sta te Departments of Agriculture, and physician reports to state Departments of Health. Although both occupational and non-occupational incidents are included in the database, SENSOR

-Pesticides focuses on occupational pesticide incidents, and is of particular value in provid ing that information. The state coordinator at each of the 11 respective state Departments of Health conducts case followup activities such as obtaining med ical records to verify symptoms and severity. Using standardized protocol and case defini tions derived from poison cent er reporting, the state SENSOR-Pesticide coordinator enters the incident information into the state-based system which is sent to NIOSH annually to be aggregated. A query of SENSOR-Pesticides 1998-2009 finds no cases involving DMDS.


### c . Agricu ltural Health Study (AHS) 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
Page 3 of4pesticide 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/seeping 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. DMDS is not included in the AHS, and therefore this study does not provide information for this report.


### IV. CONCLUSION Based on the low frequency and severity of incident cases reported for DMDS in both IDS and SENSOR-Pest icides, 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.

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