The chapter explores the intricate relationship between health and environmental hazards, emphasizing how ecological factors significantly influence public health outcomes. Environmental hazards encompass a broad range of elements, including pollution, climate change, and natural disasters. Chemicals such as pharmaceutical wastes, personal care products (PCPs), microplastics (MPs), and nanomaterials (NMs) are detected in groundwater, soil, and air, which leads to an imbalance in the ecological system and directly or indirectly impacts human health. Traditional environmental monitoring methods often fail to adequately identify these chemicals, which can link exposure to serious health conditions such as cancer, neurological disorders, reproductive issues, and endocrine disruptions, all of which pose risks to human health. However, we also elaborate on some new detection techniques to easily monitor water, soil, and air pollution. Currently, pollutants and environmental hazards are the critical challenges for their management in metropolitan cities. However, emphasizes the urgent need for advanced detection technologies, rigorous regulatory frameworks, and sustainable waste management practices to address the challenges posed by emerging pollutants. Proactive and interdisciplinary approaches are essential for minimizing the associated risks and protecting both public health and environmental quality. This chapter discusses various pollutants, such as particulate matter (PM), toxic chemicals, pharmaceutical wastes, emerging contaminants (ECs), and their direct associations with chronic illnesses like respiratory diseases, cardiovascular disorders, and cancer. ​In conclusion, it asserts that addressing health and environmental hazards is essential for achieving a sustainable and equitable future.