Today, humankind faces a number of public health challenges. These include outbreaks of vaccine-preventable diseases such as measles and diphtheria, the rise of drug-resistant pathogens, the rising prevalence of obesity and physical inactivity, the health consequences of environmental pollution and climate change, and numerous humanitarian disasters. The World Health Organization is launching its new five-year strategic plan, the Thirteenth General Work Program. This plan is subordinate to the goal of three billion: ensuring health coverage for an additional 1 billion people, protecting an additional 1 billion people from health emergencies, and improving the health and well-being of an additional 1 billion people. To achieve these goals, threats to public health must be viewed from a variety of angles. Nine out of ten people on Earth have to breathe polluted air every day. Air pollution is the environmental factor that poses the greatest risk to human health. Microscopic particles that pollute the air can penetrate the respiratory and circulatory systems and disrupt lung, heart and brain function. An estimated 7 million people die prematurely each year from illnesses caused by air pollution (including cancer, stroke, heart and lung disease). Approximately 90% of these deaths occur in low- and middle-income countries with high emissions from industry, transportation, and agriculture, as well as from the use of environmentally unfriendly cooking stoves and household fuels. Non-communicable diseases such as diabetes, cancer, and heart disease together account for more than 70% of all deaths worldwide (41 million deaths). This figure includes 15 million premature deaths between the ages of 30 and 69. More than 85% of these premature deaths occur in low- and middle-income countries. The rising prevalence of these diseases is caused by five major risk factors: tobacco use, lack of physical activity, harmful use of alcohol, unhealthy diets, and air pollution. The same risk factors also contribute to mental health disorders, which can develop from an early age: half of all mental illnesses manifest themselves by the age of 14, but in most cases they are not diagnosed or treated. For example, the third most common cause of death among 15-19 year olds is suicide. More than 1.6 billion people (22% of the world's population) live in places where there is no access to basic care due to prolonged crises (caused by a combination of factors such as drought, famine, conflict, and displacement) and poorly organized health care. Fragile areas are found in almost every region of the world, and it is in these places that half of the key Sustainable Development Goal targets, including those related to maternal and child health, remain unmet. These countries continue to work on strengthening health systems, making them better prepared to detect and respond to disease outbreaks, and building their capacity to provide high-quality health services, including immunization. The advent of antibiotics, antivirals and antimalarials are among the great successes of modern medicine. However, the era of these drugs is coming to an end. Resistance to antimicrobials (i.e., the ability of bacteria, parasites, viruses and fungi to resist their action) threatens to take us back to a time when infections such as pneumonia, tuberculosis, gonorrhea and salmonellosis were not easily cured. Failure to prevent infections can seriously impede surgical interventions and treatments such as chemotherapy. Resistance to antituberculosis drugs is a huge obstacle in the fight against the disease, which affects about 10 million people each year, of whom 1.6 million die. Drug resistance results from the inappropriate use of antimicrobials in medicine and veterinary medicine (especially in livestock), as well as from the release of antibiotics into the environment. The Department of Health is working with these sectors to implement a global action plan to combat antimicrobial resistance, which includes raising awareness of the problem, leading infection prevention, and promoting the rational use of antimicrobials.