It is not Risky, it is Healthy. Assessing of Soil Enzymatic Activity, Heavy Metal Contamination, and Health Risk for Urban Gardens Land Development in Warsaw, Poland

ABSTRACT Urban gardens (UG) in densely populated cities serve as vital spaces, fostering community well‐being, biodiversity, and local food production. Yet, these gardens face a growing threat from air and soil contamination, particularly in cities like Warsaw (Poland), where proximity to major roads, an international airport, and industrial activities elevates the risks. This study, focusing on six UGs in Warsaw, assessed the soil (including potentially toxic elements (PTE) content using spectrophotometric method, soil toxicity and health risks using OECD 208 test method and US EPA Hazard identification method) and air quality (PM 2.5 concentration) recorded at 1.5 m with a calibrated Nephelometer. The results revealed that soil PTE concentrations remained low, with dehydrogenase activity (DHA) and phytotoxicity tests showing no toxic effects. Both microbial activity and plant growth were unaffected by pollution levels, suggesting that these UGs maintain healthy ecosystems. Moreover, health risk assessments confirmed no significant risks associated with exposure to garden soils for either adults or children. The reduction of PM 2.5 levels within the gardens further highlights their role as protective green spaces. These findings support the idea that UGs, even in areas exposed to urban stressors, do not pose significant environmental or health risks, making them safe, and valuable components of urban infrastructure.