About the Pesticide Poisoning Data

This page provides general information about pesticide poisoning and measures developed by the Minnesota Environmental Public Health Tracking (MN Tracking) Program. For more information about these data, contact MN Public Health Data Access.

Information on this page:

What these data tell us:

For possible unintentional, non-occupational pesticide exposures and poisonings in Minnesota:

  • The numbers and rates of hospitalizations and emergency department (ED) visits by year, month, region, gender, or age group in Minnesota.
  • If a segment of a population is at higher risk for hospitalization or a visit to the ED.
  • The number of poison control system calls by month, pesticide type, gender, or age group in Minnesota.
  •  The demographics of calls to the poison control system.
  •  If a measure is going up or down over time.

How we can use these data:

  • Provide information to the public about unintentional, non-occupational pesticide poisoning hospitalizations, ED visits, and poison control system calls in Minnesota.
  • State and local partners can use these data for program planning and evaluation.
  • Inform prevention guidelines and for targeted public awareness & prevention campaigns during peak times of accidental poisoning.
  • MDH internal partners such as the Injury & Violence Prevention Unit, the Minnesota Depatment of Agriculture, and the Minnesota Department of Public Safety can use these data to inform their programs.

What these data cannot tell us:

  • The total burden of pesticide poisoning in a population.
  • The number or rate of occupational pesticide poisonings in Minnesota.
  • The number or rate of unintentional pesticide poisonings in Minnesota. Because personal identifiers are removed from the hospital discharge data before analysis, we cannot identify individuals who may receive care at more than one facility.

 The source of the data:

  • Hospitalization and ED data are extracted from Minnesota Hospital Discharge Data (MNHDD), which the Minnesota Hospital Association (MHA) maintains.
    • MHA data are periodically revised by the MHA to reflect more complete and accurate discharge information.
  • Poison control system calls are provided by the Minnesota Poison Control System, located at the Hennepin County Medical Center in Minneapolis. The Poison Center is certified as a Regional Poison Control Center by the American Association of Poison Control Centers.

How the measures are calculated:

Number:

  • The number indicates the total number of hospitalizations, ED visits, or calls.
  • To protect an individual's privacy, hospitalizations and ED visit counts from 1 to 5 are suppressed if the underlying population is less than or equal to 100,000.

Rate:

  • A rate is a ratio between two measures with different units. In our analysis a rate is calculated using a numerator (the number of pesticide poisoning hospitalizations, ED visits, during a period of time) divided by a denominator (the number of people at risk in a population during the same period of time). This fraction is then multiplied by 100,000. Mid-year Minnesota population estimates from the U.S. Census Bureau are used to calculate a rate.
  • To protect an individual's privacy, rates based on hospitalization or ED visits counts from 1 to 5 are suppressed if the underlying population is less than or equal to 100,000.
  • Rates based on counts of 20 or less are flagged as unstable and should be interpreted with caution. These rates are unstable because they can change dramatically with the addition or subtraction of one case.
  • An age-adjusted rate is an overall summary measure that helps to control for age differences between populations. A weighted average, called the "direct method," is used to adjust for age. The U.S. 2000 standard population is used as the basis for weight calculations.
  • Age-adjusted rates are useful when comparing the rates of two population groups that have different age distributions.

How  pesticide poisoning hospitalizations, ED visits, and calls are identified:

Hospitalizations/ED visits:

  • The data source for hospitalizations and ED visits is the Minnesota Hospital Discharge Data. The Minnesota Hospital Discharge Data collects hospital discharge information from acute care hospitals and submits the data to the MHA.
  • Hospitalizations include out-of-state hospitalizations of Minnesota residents in the nearby states of North Dakota, South Dakota, and Iowa. ED visits only include out-of-state hospitalizations of Minnesota residents after the year 2005.
  • Minnesota residents who are hospitalized or visit the ED with a diagnosis of unintentional, non-occupational pesticide poisoning, defined as having any of the following ICD-9-CM codes: 989.0-989.4, E863.0-E863.9, and E980.7. Those with ICD-9-CM codes of E861.4, E950.6, E849.1, E849.2, or E849.3 or worker's compensation as the primary payer were excluded (63 were excluded for the eleven years).

More information about the ICD9 codes.

Poison Control System Calls:

  • Minnesota residents who called the Minnesota Poison Control  System from 2005-2012 concerned about possible pesticide exposure.
  • The calls were restricted to pesticide exposures according to the National Poisoning Data System codebook for pesticides.
  •  Information calls, occupational exposures, non-human exposures, calls from outside of MN, and suspected suicides, intentional abuse, and malicious use calls were excluded.
  • The miscellaneous category was re-categorized as the following: borates/boric acid and arsenic pesticides were categorized as insecticides and metam sodium was categorized as fumigants.

 The limitations of the data:

Hospitalizations/ED visits:

  • Symptoms of pesticide poisoning often mimic colds or flu symptoms. Therefore, pesticide poisonings are often misdiagnosed and under-reported. Immediate symptoms may not be severe enough that a person seeks medical care, or a doctor may not think to ask about pesticide exposure. This may result in uncounted hospitalizations or ED visits and an underestimation of pesticide poisonings.
  • Before 2005, ED visits did not include out-of-state ED visits for Minnesota residents. Minnesota residents discharged from Wisconsin facilities are not included, so hospitalization and ED rates for counties in which residents are likely to receive care from Wisconsin may be underestimated. Rates for counties whose residents are likely to visit hospitals that do not submit data to the Minnesota Hospital Association (e.g., Veteran's Administration or Indian Health Services hospitals) may also be artificially low.
  • Multiple hospital or emergency department admissions by the same patient cannot be identified, and are not excluded.
  • Since only people with the most severe or acute symptoms of pesticide poisoning are hospitalized or  treated at the ED, these data are not appropriate for estimating the total burden of pesticide poisoning in a population. The actual number of Minnesotans who experience pesticide poisoning is unknown. Pesticide poisoning is not currently a condition that requires reporting to the Minnesota Department of Health.

Poison Control System Calls:                                           

  • The public seek medical counsel for poisoning, which is verified by follow-up phone calls by poison system specialists. These calls represent suspected exposures from pesticides and serve as a proxy to estimate the burden of pesticide poisonings. An actual poisoning event can only be verified through a confirmed medical diagnosis.
  • Data acquired by telephone are limited to those who have access to telephones and knowledge of the poison system service. An unknown number of pesticide exposure events may occur for which no call was made.
  • The poison control system data only provides the location of the caller, not the patient's residence or geographic location of the poisoning.
  • The work-related information is not systematically reported, so some occupational poisonings may be accidentally included in this pesticide poisoning data, designed to evaluate and track poisonings from residential/consumer pesticide use.
  • It is difficult to determine if more than one call was made for the same event. While the poison specialists try to prevent this from occurring, it is possible there are numerous calls for the same poisoning event.

More technical information about the data:

To learn more about regulatory and monitoring requirements related to pesticides, contact the Minnesota Department of Agriculture.   To learn more about pesticide toxicity and exposure, see MDH Pesticide Information.

For more information about the data and measures developed by the MN Tracking Program, contact the Data Access portal.