Chemicals that mimic or antagonize the actions of naturally occurring estrogens are defined as having estrogenic activity (EA), which is the most common form of endocrine...
HerbicideLast Updated on 2014-10-26 16:45:24A 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 »
Plastic products and estrogenic chemicalsLast Updated on 2014-06-14 12:26:55Chemicals that mimic or antagonize the actions of naturally occurring estrogens are defined as having estrogenic activity (EA), which is the most common form of endocrine disruptor activity.
This article, written by Chun Z. Yang, Stuart I. Yaniger, V. Craig Jordan, Daniel J. Klein, and George D. Bittner* 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.
Most Plastic Products Release Estrogenic Chemicals:
A Potential Health Problem That Can Be Solved
Background: Chemicals having estrogenic activity (EA) reportedly cause many adverse health... More »
TetrodotoxinLast Updated on 2014-05-20 15:07:08
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 was the first to record TTX poisoning in western literature in 1774 following an incident caused by ingesting fish from the family Tetraodontidae (commonly known as puffer fish). Incidents of poisonings in China due to consumption of puffer fish have been dated as far back as 2000 years.
TTX, produced by bacteria or dinoflagellate species, is an alkaloid substance with a guanidinium group (including three nitrogen atoms, blue in Figure 1), a pyrimidine ring (red in Figure 1) and five other ring systems. It is a thermostable non-protein and it is soluble in water.
Figure 1: Molecular Structure of Tetrodotoxin
TTX acts on both central and peripheral nervous systems. Also, it... More »
Organic farmingLast Updated on 2014-05-01 17:45:47Organic farming is a form of agriculture that relies on crop rotation, green manure, compost, biological pest control, and mechanical cultivation to maintain soil productivity and control pests, excluding or strictly limiting the use of synthetic fertilizers and synthetic pesticides, herbicides, plant growth regulators, livestock feed additives, and genetically modified organisms. Arguably, the term can be interpreted to include animal husbandry practices. Also, often there is confusion as to use of the term organic farming, especially since many food processors choose to use the term organic to induce consumers to purchase a food brand, even though all the standards of organic farming may not have been met.
Organic agricultural methods are regulated internationally and enforced legally by many nations, based in large part on the standards set by the International Federation of Organic... More »
Public Health Statement for DDT, DDE, and DDDLast Updated on 2013-10-01 23:28:36This article is a verbatim version of the original and is not available for edits or additions by EoE editors or authors. Companion articles on the same topic that are editable may exist within the EoE.
CAS#: DDT 50-29-3, DDE 72-55-9, DDD 72-54-8
This Public Health Statement is the summary chapter from the Toxicological Profile for DDT, DDE, and DDD. It is one in a series of Public Health Statements about hazardous substances and their health effects. A shorter version, the ToxFAQs™, is also available. This information is important because this substance may harm you. The effects of exposure to any hazardous substance depend on the dose, the duration, how you are exposed, personal traits and habits, and whether other chemicals are present. For more information, call the ATSDR Information Center at 1-888-422-8737.
This public health... More »
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