Human Health

From the physical and social well-being of an individual to the functioning of an ecosystem, health has many different meanings and applications. More than just the absence of disease, health implies a state of well-being. Ever since the origin of life, physical, chemical and biological factors have impacted the health or biological status of living things. And in response life has evolved immune systems, detoxification systems and redundancies to stave off infection, disease, and toxicity. As the world becomes more interconnected, and industrialized, diseases never seen in one part of the globe now threaten to devastate human, wildlife and plant populations, while industrial chemicals now contaminate life in the most remote regions. Maintaining health, whether ecosystem, human or microbial arguably presents one of the greatest challenges of the day. 

  • Respiration Featured Article Respiration Respiration

    Respiration is the gas exchange effected by living organisms for the purpose of sustaining vital metabolic processes. In the case of most animals, oxygen is taken into the... More »

  • Tetrodotoxin Featured Article Tetrodotoxin Tetrodotoxin

    Tetrodotoxin (abbreviated as TTX) is a powerful neurotoxin found in a variety of animals and is responsible for upwards of 50 human fatalities a year. Captain James Cook... More »

  • Botulism and home canning Featured Article Botulism and home canning Botulism and home canning

    Home canning is an excellent way to preserve garden produce and share it with family and friends, but it can be risky or even deadly if not done correctly and... More »

  • Estimation of adult human biomass Featured Article Estimation of adult human biomass Estimation of adult human biomass

    The energy requirement of species at each trophic level is a function of the number of organisms and their average mass. The study estimates global human biomass, its... More »

Recently Updated
Water pollution Last Updated on 2014-11-17 12:18:45 Water pollution is the contamination of natural water bodies by chemical, physical, radioactive or pathogenic microbial substances. Adverse alteration of water quality presently produces large scale illness and deaths, accounting for approximately 50 million deaths per year worldwide, most of these deaths occurring in Africa and Asia. In China, for example, about 75 percent of the population (or 1.1 billion people) are without access to unpolluted drinking water, according to China's own standards.[1] Widespread consequences of water pollution upon ecosystems include species mortality, biodiversity reduction and loss of ecosystem services. Some consider that water pollution may occur from natural causes such as sedimentation from severe rainfall events; however, natural causes, including volcanic eruptions and algae blooms from natural causes constitute a minute amount of the... More »
Ecosystems and Human Well-Being: Volume 1: Current State and Trends: Air Quality and Climate Last Updated on 2014-11-17 12:15:25 This is Chapter 13 of the Millenium Ecosystem Assessment report Ecosystems and Human Well-Being: Volume 1: Current State and Trends Coordinating Lead Authors: Jo House, Victor Brovkin Lead Authors: Richard Betts, Bob Constanza, Maria Assunçao Silva Dias, Beth Holland, Corinne Le Quéré, Nophea Kim Phat, Ulf Riebesell, Mary Scholes Contributing Authors: Almut Arneth, Damian Barratt, Ken Cassman, Torben Christensen, Sarah Cornell, Jon Foley, Laurens Ganzeveld, Thomas Hickler, Sander Houweling, Marko Scholze, Fortunat Joos, Karen Kohfeld, Manfredi Manizza, Denis Ojima, I. Colin Prentice, Crystal Schaaf, Ben Smith, Ina Tegen, Kirsten Thonicke, Nicola Warwick Review Editors: Pavel Kabat, Shuzo Nishioka Main Messages Ecosystems, both natural and managed, exert a strong influence on climate and air quality. Ecosystems are both sources and sinks of greenhouse gases,... More »
Animal food Last Updated on 2014-11-15 15:14:46 The U.S. Department of Agriculture's Food Safety and Inspection Service (FSIS) defines Animal Food as: Any article intended for use as food for dogs, cats, or other animals derived wholly, or in part, from the carcass or parts or products of the carcass of any livestock, except that the term animal food as used herein does not include: Processed dry animal food or Livestock or poultry feeds manufactured from processed livestock byproducts (such as meatmeal tankage, meat and bonemeal, bloodmeal, and feed grade animal fat).   More »
Herbicide Last Updated on 2014-10-26 16:45:24 A herbicide is any of a number of chemical substances intended to kill vegetation. Since the vast majority of herbicides are non-selective in their lethal action, there may be widespread adverse ecological consequences from their use. These outcomes include not only organism death, but may involve mutagenic, developmental and carcinogenic effects to animals and plants. Herbicides are in broad use for agriculture, golf courses, utility corridors, residential and other land uses. The earliest herbicides were inorganic chemical substances, although modern herbicides are dominated by organic compounds. Presently, there is massive application of chemical herbicides; in the USA alone 480 million kilograms are applied annually. Widespread herbicide use beginning in the 1940s is responsible for numerous species extinctions, including birds, amphibians, fish and arthropods. In many cases,... More »
Gut reaction: environmental effects on the human microbiota Last Updated on 2014-10-13 22:34:38 This article, written by Melissa Lee Phillips, appeared first in Environmental Health Perspectives—the peer-reviewed, open access journal of the National Institute of Environmental Health Sciences. The article is a verbatim version of the original and is not available for edits or additions by Encyclopedia of Earth editors or authors. Companion articles on the same topic that are editable may exist within the Encyclopedia of Earth. Living with each of us—on our skin, in our mucosa, and in our gastrointestinal (GI) tract—are microorganisms whose numbers dwarf the number of our own cells and genes. Although some of these microbes are pathogens, most are harmless or even beneficial. The body’s assortment of microorganisms, collectively called the microbiota, is similar to an organ in that it performs functions essential for our survival. Some microbes produce... More »