The concern about unexplained sickness at home is valid, as slow leaks from household gases can compromise health without immediate, obvious danger. Many homes contain appliances that use or produce gaseous substances, and a malfunction can release these compounds into the living space at low levels over time. Understanding the different types of gases involved and the specific symptoms they cause is the first step toward safeguarding your health.
The Two Primary Household Gas Threats
The average home relies on two distinct types of gases that present different hazards when a leak occurs: natural gas and carbon monoxide. Natural gas, which is primarily methane, is the fuel source used for heating, cooking, and hot water. In its pure state, methane is naturally colorless and odorless, making it impossible to detect by human senses alone.
To prevent explosive hazards, utility companies add a compound called mercaptan to the gas supply before it reaches your home. Mercaptan contains sulfur and creates the odor often described as rotten eggs or decaying vegetables. This odorant is a safety measure, designed to be detectable by people at extremely low concentrations, before the gas poses a fire or explosion risk.
The second, and more insidious, threat is carbon monoxide (CO), which is a byproduct rather than a fuel source. CO is a gas produced by the incomplete combustion of carbon-containing fuels like natural gas, propane, wood, or kerosene. Sources in the home include furnaces, gas water heaters, fireplaces, and gas stoves.
Unlike natural gas, carbon monoxide is entirely colorless, odorless, and tasteless. While natural gas leaks primarily pose a sudden explosion risk, CO is a systemic poison that can accumulate slowly due to a faulty appliance or blocked vent, leading to health problems without any external warning.
Chronic Symptoms Associated with Slow Leaks
The mechanism by which carbon monoxide makes a person sick involves its effect on the blood. When inhaled, CO bypasses oxygen and binds directly to the hemoglobin in red blood cells to form carboxyhemoglobin. Hemoglobin is the protein responsible for transporting oxygen, and CO’s affinity for it is hundreds of times greater than oxygen’s.
This binding effectively displaces oxygen, reducing the blood’s capacity to deliver it to organs and tissues, a state known as hypoxia. The body’s most oxygen-demanding organs, such as the brain and heart, are the first to experience the negative effects of this deprivation. Chronic, low-level exposure is particularly dangerous because the symptoms are subtle and easily confused with other common ailments.
A persistent, dull headache is a primary symptom of chronic CO poisoning. Victims also commonly experience fatigue, dizziness, and general weakness that does not improve with rest. These symptoms often worsen when a person is at home and improve when they leave the building, though this pattern is not always immediately recognized.
Gastrointestinal symptoms like nausea and vomiting may also be present, contributing to the misdiagnosis of the problem as a stomach bug or the seasonal flu. Cognitive changes, such as mild confusion, difficulty concentrating, and memory loss, are also associated with prolonged exposure. These neurological effects stem from the lack of oxygen reaching the brain over an extended period.
In some cases, the symptoms can be so vague that they are mistaken for chronic fatigue syndrome, depression, or other non-gas-related health issues. This delayed or incorrect diagnosis is a defining characteristic of slow-leak exposure. Unlike acute poisoning, which causes severe, sudden symptoms like loss of consciousness or collapse, chronic poisoning requires individuals to consider their home environment as a potential source of persistent, unexplained malaise.
Immediate Detection and Emergency Protocol
Because natural gas is odorized, detection relies on recognizing the rotten-egg smell of the mercaptan additive. If you smell this odor, the situation must be treated as an immediate fire and explosion hazard. The protocol is to evacuate the premises immediately and ensure everyone else leaves the building.
Do not use any electrical switches, including lights, the phone, or opening a garage door, as a spark could ignite the gas. Once you are a safe distance away from the building, you should use a mobile phone to call the local gas utility company or 911 to report the leak.
Detection for carbon monoxide is different, as it cannot be smelled. Therefore, the use of electronic detectors is the only reliable safety measure. These CO alarms should be installed on every level of the home and near all sleeping areas, and they must be tested regularly. If a carbon monoxide alarm sounds, the immediate response is identical to a natural gas leak: evacuate the building and get into fresh air immediately.
Do not attempt to locate the source of the CO or open windows from inside the home, as evacuation is the priority. Once safely outside, call the fire department or 911 for emergency medical services if anyone is experiencing severe symptoms. Do not re-enter the building until emergency responders have determined that the air is safe and the source of the gas has been identified and corrected.