This section introduces the connection between environmental quality and human health. It explains why the topic concerns both biology and everyday life, defines the main terms, identifies the central problem, and briefly presents the project’s focus on environmental factors, health effects, evidence, and practical prevention.

This theoretical section defines environmental health as the study of how physical, chemical, biological, and social surroundings influence people. It distinguishes natural factors from human-made ones and explains why the same exposure can produce different effects depending on concentration, duration, age, genetics, and general health.

The section describes major pollutants found in air, water, and soil, including fine particles, toxic gases, heavy metals, pesticides, and disease-causing organisms. It explains routes of exposure through breathing, drinking, eating, and skin contact, as well as possible effects on the lungs, nervous system, digestion, and circulation.

This part examines noise, ultraviolet radiation, temperature, humidity, microorganisms, and allergens as health-related environmental factors. It explains mechanisms such as stress responses, tissue damage, heat loss problems, allergic inflammation, and infection, using examples that are understandable for secondary school students.

The section shows how environmental conditions interact with human behavior and living spaces. It considers ventilation, hygiene, waste disposal, transport, physical activity, tobacco smoke, access to green areas, and public health rules, emphasizing that prevention often depends on both individual actions and community infrastructure.

This methodological section presents ways to collect and evaluate information, including analysis of official statistics, observation, questionnaires, comparison of sources, and simple measurements. It explains how to avoid biased questions, protect respondents’ privacy, separate correlation from causation, and report results honestly.

This practical section describes a small survey or observation of environmental habits and perceived risks among students or family members. The results are organized into tables and charts, then interpreted with attention to sample size, possible errors, and the difference between personal opinions and scientifically established health effects.

This section develops realistic recommendations based on the theoretical evidence and collected data. It addresses indoor air, drinking water, hygiene, sun protection, noise, waste, and behavior during extreme weather, explaining which actions reduce exposure and which problems require support from schools, communities, or public authorities.

The conclusion summarizes the main links between environmental conditions and human health without introducing new evidence. It connects the biological mechanisms with the practical findings, identifies the most significant preventable risks, evaluates the usefulness of the recommendations, and emphasizes responsible behavior supported by reliable scientific information.

This final section lists the textbooks, scientific publications, official health reports, and verified online resources used in the project. Each source is recorded in a consistent format so that readers can check the evidence, distinguish facts from opinions, and find additional information about environmental risks and prevention.