POPULATION GROWTH AND DEMOGRAPHIC SHIFTS: CHALLENGES TO PUBLIC HEALTH

Public health personnel and medical geologists focussed on conditions that keep people safe from disease and physical harm must be alert to growing global populations and demographic shifts. As rural citizens flock to cities, they establish edge districts that grow as shantytowns/slums, overcrowded, poor, and often lack clean water, adequate sanitation, garbage/waste collection, safe housing, electricity, and other "good life" amenities. These are mainly in Asia, Africa, and South America, and in 2018 house nearly one billion people that may grow to 1.7 billion by 2050. Examples discussed include Karachi, Mumbai, Lagos, Lima, and Mexico City. This increases a public health burden. Squalid, densely populated urban areas are more likely to suffer the effects of air and water pollution, infectious diseases, and habitation of physically at risk zones than do city core residents. The former include premature death from inhalation of <2.5𝜇 particles, sicknesses as diarrheal diseases, dengue fever, and ingestion of toxins through air, water, and/or food that may bioaccumulate in body organs to sicken, incapacitate, or kill people. The latter are locations with a history of hazards that include flooding, and triggered ones (e.g., landslides, tsunamis) generated by a primary event.

Epidemiologists uncover disease nodes at densely populated cities. Medical geologists work to trace the sources of citizens' health problems. Once identified, they suggest solutions to eliminate them or mitigate their impact. This may be via laws that require best available pollutant capture modules in industries. It may be by finding new water sources and/or by installing new water treatment plants. It may be by proposing flood defense schemes or by legislating zoning that prevents habitation of risk areas, and by strictly following building codes. Economic resources limit what can be done but funding can be found (e.g., World Bank, regional development banks), but enough? Public health preparedness is essentials as are search and rescue teams and warning systems that alert threatened urbanites to seek care or evacuate to safety. Lastly, medical geologists must plan for IPCC projected changes that increasingly affect global health burdens.