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Frequently Asked Question - Unintentional Carbon Monoxide (CO) Poisoning

What is carbon monoxide (CO)?

Carbon monoxide (CO) is a colorless, odorless, poisonous gas. It is produced by the incomplete burning of various fuels, including gasoline, coal, wood, charcoal, oil, kerosene, propane, and natural gas. Products powered by internal combustion engine such as portable generators, automobiles, lawn mowers, and power washers produce CO.

What is CO Poisoning?

The most common symptoms of CO poisoning are headache, dizziness, fatigue, nausea or vomiting, trouble thinking, diarrhea, weakness, and shortness of breath. However, these symptoms can also point to other illnesses. If a patient complains of those symptoms, but does not have a fever, CO poisoning should be considered and a focused history with exposure to CO sources should be taken. Severe CO poisoning is less difficult to diagnose. Any organ can be affected by CO poisoning. In addition to headache and subjective trouble thinking, patients may show confusion, slowed thought processing, irritability, ataxia, seizures, or loss of consciousness. Cardiovascular involvement may result in hypotension, arrhythmias and even myocardial ischemia or infarction. Pulmonary/respiratory distress might include pulmonary edema, tachypnea or respiratory arrest.

Why is the Massachusetts Department of Public Health tracking CO as a public health issue in the state?

The U.S. Centers for Disease Control and Prevention (CDC) worked with EPHT state partners to develop nationally consistent data measures (NCDM) for environmental and health data. Unintentional CO poisonings is a NCDM. The EPHT program has identified the need for surveillance for unintentional CO poisonings to support public health prevention and intervention activities. Tracking the occurrence of CO poisonings can also provide information on unrecognized exposures such as spikes in CO poisoning after disasters and storms due to emergency generator use.

Where does CO come from?

The leading source of non-fire, unintentional CO poisoning is from indoor home heating sources such as furnaces, water heaters, space heaters, lanterns, stoves, and similar appliances. In the northern region of the US most CO poisoning cases occur during the winter heating season. CO poisoning also occurs most often after a power outage, when loss of electrical power leads to increased use of gasoline-powered generators, kerosene space heaters, charcoal and hibachi grills, propane stoves, and charcoal briquettes for both cooking and heating indoors. Except for space heaters, none of these devices should ever be used inside the home, basement, garage, camper, tent, or outside near an open window.

Who is likely to be affected by exposure to CO poisoning ?

A person(s) suffering from heart or respiratory health problems, infants and small children, unborn children, expectant mothers, and pets can be affected by CO poisoning faster than others and may be the first to show symptoms.

How can I reduce my exposure to CO poisoning?

  • Heating systems, water heaters, and any other gas, oil, or coal burning appliances should be serviced by a qualified technician every year.
  • Service experts should be called if an odor from a gas refrigerator's cooling unit is detected. That could mean there is a defect in the cooling unit which could be giving off CO.
  • When purchasing gas equipment, people should only buy equipment carrying the seal of a national testing agency, such as the American Gas Association or Underwriters' Laboratories.
  • Appropriate venting of gas appliances in a home, cabin, or camper can help avoid CO build-up. Indoor vent pipes should go up slightly as they go toward outdoors. This helps prevent CO or other gases from leaking if the joints or pipes aren't fitted tightly.
  • Chimneys should be checked and cleaned every year to be sure they are not blocked by debris.

There are steps people can take in their automobiles and other motorized equipment to prevent CO poisoning.

  • Have a mechanic check the exhaust system every year. Just a small leak in a car's exhaust system can lead to an increase in CO inside the car.
  • Introducing emissions control devices to propulsion engines on recreational boats could also help to reduce CO concentration in the exhaust, thus reducing the risk of CO poisoning.
  • Recreational boaters should turn off the motor before swimming or body surfing. Exposure to the exhaust system while the engine or generator is running can expose the swimmer to CO.

How are the EPHT measures for CO poisoning calculated?

Hospitalization data reported on this website are obtained from the Massachusetts Division of Health Care Finance and Policy. This agency collects emergency department data and inpatient hospital admissions data for all Massachusetts acute care hospitals and satellite emergency facilities. Mortality data is obtained from the Massachusetts Registry of Vital Records and Statistics. Statewide rates are calculated by applying specific diagnostic codes to each of the three categories of CO poisoning (i.e., fire-related, non-fire related, and unknown).

How do I interpret a rate, and what is the difference between age-specific, crude, and age-adjusted rates?

An incidence rate tells us how often a hospitalization event occurs in a population. An age-specific rate for CO poisoning is calculated for each age group to show how the incidence of CO poisoning changes with age. A crude rate for CO poisoning is the number of CO poisoning admissions over a specified period of time divided by the total population. An age-adjusted rate enables comparisons to be made between populations which have different age structures.

What are the limitations associated with the NCDMs for CO poisoning?

  • The data are presented only at the statewide level. Information about specific sources of CO poisoning is not presented.
  • Hospitalization data, by definition, exclude discharges from specialty hospitals (e.g., psychiatric), long-term care facilities, and federal hospitals that are exempt from state reporting requirements.
  • Transfers from one hospital to another are excluded from the data.
  • Numbers and rates may differ slightly from those reported on the national EPHT portal. These differences may be due to file updates, differences in calculation methods (such as grouping ages differently or rounding off numbers at different points in calculations), and updates or differences in population estimates.
  • Hospitalization data will only be presented to the public if the confidentiality rules of MDPH and the Massachusetts Division of Health Care Finance and Policy are met. These are rules requiring data aggregation and cell suppression to protect privacy.
  • Differences in rates between jurisdictions may reflect differences in hospital admissions practices for treating persons with severe CO poisoning. For example, some facilities may routinely admit all patients treated with hyperbaric oxygen, while others may release such patients after they complete the treatment if they are determined to be in stable condition.
  • Incidence rates are based on the residential address of patients and not necessarily the location of the source of exposure.

What is the regulation for CO in Massachusetts?

On November 4, 2005, "Nicole's Law" was signed into law requiring CO detectors in all Massachusetts homes with potential sources of CO including those with fossil-fuel burning equipment or enclosed parking areas. "Nicole's Law" was named after 7-year old Nicole Garofalo who died on January 28, 2005 as a result of her Plymouth home being filled with deadly amounts of CO on January 24. The furnace vents had been blocked by snow during a significant storm. The regulations (527 CMR 31.00) establish requirements of the law including the type, location, maintenance, and inspection requirements for CO alarms. Provisions of the law include the following: For buildings with fossil-fuel burning equipment or enclosed parking areas, the new regulations require CO detectors on every level of the home and within ten feet of each sleeping area and in habitable portions of basements and attics. The CO alarms must be approved by an independent testing laboratory such as Underwriter's Laboratory (UL).

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