A bong is a water pipe designed as a filtration device for smoking plant material, typically cannabis. Users often draw smoke through a water chamber before inhaling it, which is widely believed to make the smoke cleaner and less harsh. This common assumption suggests that the water acts as an effective filter, trapping harmful components and reducing health risks. However, the physical and chemical processes at work are more complex, and scientific evidence reveals this method introduces distinct health concerns. This article explores the science behind water filtration and examines the specific risks associated with using a water pipe.
The Effectiveness of Water Filtration
Water filtration achieves a noticeable cooling effect on the smoke, which reduces the harshness felt in the throat and lungs during inhalation. The water also effectively traps larger particles, such as ash and heavier particulate matter, which is visible as the water becomes discolored with use. However, the effectiveness of water at filtering out harmful chemical compounds is significantly limited.
Many of the most concerning toxins produced during combustion, such as polycyclic aromatic hydrocarbons (PAHs) and various non-polar, fat-soluble carcinogens, are not readily soluble in water. These substances pass through the water chamber and into the lungs with little reduction in concentration. Gases like carbon monoxide are also not trapped by the water and are inhaled by the user.
Research indicates that water filtration filters out more of the psychoactive compound, tetrahydrocannabinol (THC), than it filters out tar. This skewed ratio means that a user must consume a greater volume of smoke to achieve the desired effect, thereby exposing their lungs to a higher overall dose of harmful tar per unit of THC. The resulting smoke has a worse tar-to-cannabinoid ratio compared to methods without water filtration. This mechanism directly undermines the perception of the water pipe being a safer alternative.
Risks from Increased Smoke Volume and Temperature
The cooling and smoothing effect encourages users to take much deeper and larger inhalations, often referred to as “mega clears.” This increase in inhaled smoke volume means a greater quantity of combustion byproducts reaches the deepest parts of the lungs in a single breath. While the smoke feels cooler upon initial contact, the rapid delivery of a large volume can still expose lung tissue to a heavy dose of particulate matter and heat. This deep, forced inhalation behavior can lead to a greater deposition of total tar and toxins in the lungs per session compared to methods that naturally limit smoke volume due to harshness.
Microbial Contamination
A unique and significant risk associated with water pipes is the potential for microbial contamination. If the water is not changed frequently, the standing water and interior surfaces of the pipe become a breeding ground for mold, fungi, and various bacteria. Inhaling aerosolized water droplets contaminated with these microorganisms can lead to serious respiratory infections, including forms of pneumonia. This risk is heightened when using pipes made from materials other than glass, such as certain plastics, which can potentially leach chemicals when heated or repeatedly cleaned.
Systemic Health Effects of Combustion Byproducts
Combustion, regardless of the filtration method, creates a complex mixture of thousands of organic and inorganic chemical compounds. The smoke inhaled from a water pipe still contains numerous toxicants that can have systemic effects on the body. These byproducts include known carcinogens like benzene, acetaldehyde, ammonia, and polycyclic aromatic hydrocarbons.
Carbon Monoxide Exposure
One of the most immediate systemic risks comes from carbon monoxide (CO), a colorless and odorless gas present in the smoke. Inhaling CO reduces the blood’s capacity to carry oxygen, which places an additional burden on the cardiovascular system. This reduced oxygen delivery can lead to an acute increase in heart rate and blood pressure, potentially increasing the risk of a heart attack, especially in individuals with existing cardiovascular vulnerabilities.
Respiratory Damage
Long-term exposure to the remaining tar and fine particulate matter (PM2.5) causes chronic irritation and damage to the respiratory tract. Regular inhalation of these irritants is associated with symptoms like chronic cough, wheezing, and excessive phlegm production. Over time, this exposure can lead to chronic bronchitis and inflammation of the airways, indicating persistent physiological harm.