In the past, scientists have studied human, animal and plant diseases caused by some organisms that live in soil -- dogs get heartworm from infected soils and humans can get parasites like pinworm that live in some soils.
Valley fever, caused by a fungus thriving in desert soils, affects people and can lead to flu-like symptoms and death. Earlier this month, the Centers for Disease Control and Prevention issued a report on Valley fever and its effect on workers constructing solar power farms in San Luis Obispo County, California. The CDC predicted that without outreach programs and more awareness of Valley fever, more workers will be exposed and infected.
Anthrax, which is well-known in the United States as a bioterrorism agent, is relatively common and found in soils worldwide. Anthrax spores can remain dormant in soils for decades, but with heavy rains, they are brought to the surface and attach to roots and grasses, where animals might graze upon them, often resulting in death. Plants also are killed by pathogens, pests and diseases from the soil, which reduces crops and plant productivity.
"Diseases of humans, plants and animals caused by soil-borne organisms have traditionally been studied by separate disciplines, but the final goal should be an integration of research and knowledge, since the ultimate goal is to improve human health," said Wall.
In addition, research studies have found that exposure to microorganisms in soil lessens the prevalence of allergies. "Exposing our immune system to soil may help develop tolerance to possible pathogens," said coauthor Johan Six, Swiss Federal Institute of Technology Zurich in Switzerland.
Soils also contain a reservoir of possible sources for antibiotics and medicines, with many of the antibiotics in use today being derived from soils.
With future predictions that two-thirds of the global human population will live in urban areas by 2050, scientists also expect that our immune systems will be less stimulated by having less contact with nature. Many people already understand this concept; outdoor and nature-based preschools are popping up in urban areas from New York City to Seattle.