Chlorinated Pools and Chemical Byproducts: What Research Shows

Chlorine has long been the industry standard for keeping swimming pools safe and free of harmful bacteria. While highly effective as a disinfectant, research suggests that chlorine can form potentially harmful chemical byproducts when it reacts with organic material commonly found in pool water.

A report published by NBC News summarized findings from multiple peer-reviewed studies showing that chlorinated pools can contain more than 100 chemical disinfection byproducts (DBPs). These compounds are created when chlorine interacts with sweat, skin cells, body oils, urine, and personal care products introduced by swimmers.

While the studies do not conclude that swimming causes cancer, researchers observed short-term biological markers associated with DNA damage and respiratory irritation after relatively brief exposure.

How Chlorine Byproducts Form in Swimming Pools

Chlorine itself is not inherently dangerous at proper levels. The concern lies in what happens after chlorine reacts with organic matter in pool water.

These reactions can create:

• Chloramines, which contribute to the strong “chlorine smell” often noticed in pools

• Volatile compounds that accumulate in the air just above the water’s surface

• Disinfection byproducts linked in animal and occupational studies to asthma, airway irritation, and bladder cancer

Swimmers are exposed through:

• Skin absorption

• Inhalation of air above the pool surface

• Increased breathing during physical exertion

Indoor pools and heavily used facilities may experience higher concentrations if water is not adequately refreshed or filtered.

Health Considerations for Children and Frequent Swimmers

Researchers cited in the NBC report emphasized caution—particularly for children, competitive swimmers, and pool workers who experience repeated exposure. Some studies have shown:

• Higher asthma rates among lifeguards and competitive swimmers

• Increased eye, skin, and throat irritation in poorly ventilated or heavily chlorinated pools

• Greater sensitivity in infants and young children during early development

Importantly, experts agree that swimming remains a healthy activity. The goal is not avoidance, but reducing unnecessary chemical exposure where possible.

Reducing Chlorine Demand Without Sacrificing Pool Safety

Rather than eliminating chlorine altogether, scientists recommend strategies that reduce the amount needed to maintain sanitation. These include:

• Improved filtration and circulation

• More frequent water replacement

• Encouraging swimmers to shower before entering the pool

• Using complementary water-treatment technologies

Lower chlorine demand means fewer reactions with organic material—and fewer harmful byproducts.

How Advanced Water Treatment Supports Cleaner Pool Water

Modern systems like AquaRev Water focus on improving water quality at a physical level, rather than adding more chemicals. By using hydrodynamic cavitation, water is mechanically conditioned in a way that helps reduce organic buildup and improves overall filtration efficiency.

In practice, this can:

• Lower the amount of chlorine required to maintain safe conditions

• Reduce the formation of chemical byproducts

• Improve water clarity and swimmer comfort

• Support better air quality around pools

This approach aligns with research recommendations calling for better pool management practices rather than increased chemical use.

A Science-Based, Balanced Approach to Pool Health

The studies highlighted by NBC News reinforce an important point: chlorine is effective and necessary, but it is not without tradeoffs. Reducing exposure to chemical byproducts—especially in residential, hotel, and community pools—can improve both comfort and long-term health considerations.

By combining proper sanitation with smarter water treatment, pool owners can maintain safety while minimizing unnecessary chemical load. As research continues, approaches that reduce chlorine dependency without compromising hygiene represent a responsible evolution in pool care.