Malnutrition, Overpopulation and Environmental Problems Linked to Diseases
Pimentel and a team of Cornell graduate students examined data from more than 120 published papers on the effects of population growth, malnutrition and various kinds of environmental degradation on human diseases. Their report was published in the journal Human Ecology.
"We have serious environmental resource problems of water, land and energy, and these are now coming to bear on food production, malnutrition and the incidence of diseases," Pimentel says.
Malnutrition Kills 6 Million Children Annually
The research shows that 57 percent of the current world population of about 6.5 billion is malnourished, compared with 20 percent of the world population of 2.5 billion in 1950. Malnutrition is not only the direct cause of death for 6 million children each year, but also makes millions of people much more susceptible to deadly health problems such as acute respiratory infections, malaria and a host of other life-threatening diseases, according to the report.
Other main points of the study include:
- Nearly half the world's people are crowded into urban areas, often without adequate sanitation, and are exposed to epidemics of measles, influenza and other diseases.
- With 1.2 billion people lacking clean water, waterborne infections account for 80 percent of all infectious diseases. Increased water pollution creates breeding grounds for malaria-carrying mosquitoes, which kill 1.2 million to 2.7 million people every year. Air pollution kills about 3 million people annually. Unsanitary living conditions account for more than 5 million deaths each year, and more than half of those are children.
- Air pollution from smoke and various chemicals kills 3 million people a year. In the United States alone, about 3 million tons of toxic chemicals are released into the environment each year—contributing to cancer, birth defects, immune system defects and many other serious health problems.
- Soil is contaminated by many chemicals and pathogens, which are passed on to humans through direct contact or in their food and water. Increased soil erosion worldwide not only results in more soil being displaced, but also contributes to the spread of disease microbes and various toxins.
At the same time, more microbes are becoming increasingly drug-resistant. And global warming, together with changes in biological diversity, influence parasite evolution and the ability of exotic species to invade new areas. As a result, diseases such as tuberculosis and influenza are re-emerging as major threats while new threats—including West Nile virus and Lyme disease—have developed or spread.
Saving Lives Requires New Population Policies and Better Conservation
"A growing number of people lack basic needs, like pure water and ample food,” Pimentel says. “They become more susceptible to diseases driven by malnourishment, and air, water and soil pollutants.”
In their report, Pimentel and his co-authors call for comprehensive and fair population policies, and increased conservation of environmental resources that support human life.
"Relying on increasing diseases and malnutrition to limit human numbers in the world diminishes the quality of life for all humans and is a high-risk policy," the researchers conclude.