The popularity of Poured-in-Place (PIP) surfaces in kids' play zones stems from their soft rubber cushioning for falls and their role in recycling scrap car and truck tires. Playgrounds and sports fields often feature recycled tire crumb rubber loaded with polycyclic aromatic hydrocarbons, or PAHs, which can include carcinogenic ones. A new study warns this material may leach harmful chemicals. PAHs resist rapid degradation, lingering in soil and water long-term, threatening ecosystems and stirring concerns for human exposure risks.
Exposure happens through direct skin absorption, ingestion of crumb particles, and inhalation of released vapors or dust, amplified on hot days. This repeated contact during play heightens potential chronic health risks.
The study team examined granulate made from discarded vehicle tires, evaluating total PAH content and the bioavailable portion that dissolves in water for organism uptake. The smallest tested particles had over twice the contamination, and because they're more reactive, they release a larger fraction of toxins into the environment.
To mimic environmental threats, the team exposed soil springtails, garden cress, and marine bacteria to rubber granulate and soaked water. Springtails suffered the worst. The tiniest rubber particles killed 70% outright, and survivors couldn't reproduce at all. Even the biggest chunks killed a third and cut reproduction by over half.
The study identified potentially harmful metals including zinc and copper leaching into water from the granulate, with some concentrations above drinking-water limits, intensifying toxicity concerns.
While affirming tire recycling as an important eco-goal, the researchers cautioned that recycled products aren't always safe by default. This work highlights the need to rethink assessment protocols and usage guidelines for recycled tire granulate.
To view the original scientific study click below:
Toxicity and polycyclic aromatic hydrocarbons bioavailability in recycled tire rubber granulate of varying particle sizes
Healthy aging isn't just about living longer, it’s about staying strong enough to enjoy those extra years. New research shows that getting enough protein and combining it with resistance exercise is one of the most effective ways to preserve muscle, maintain mobility, and reduce the physical decline that often comes with aging.
Our daily routines and body rhythms tend to shift with age. Although chronological age is fixed by time, biological age reflects how well the body is functioning. A new study suggests that aging may affect circadian rest-activity rhythms, the body’s natural daily cycle that helps regulate wakefulness, activity, rest, and sleep.
Exercise may be one of the most powerful anti-aging tools we have. New research suggests it can switch aging muscles back into repair mode, helping them recover, rebuild, and stay stronger as we grow older.