Once these signals reach the target organ they bind to a receptor after which they trigger the required responses for instance regulation of body sugar or concentration of salt in body fluids. The effect of these messengers is either an increase or reduction in the target substance which is determined by either a change in environment or a need of a certain substance when its time during growth finds use in the body. Endocrine Disruptors Sometimes analogues or substances similar in structure to some of the endocrine hormones
bind to the receptors preventing the binding of the substance supposed to bind on that receptor resulting in ill health. This limits the normal physiological functions of the body. Disruption by these analogues may be by interfering with the normal hormonal balance, changing the passage routes of the hormones or by stopping hormone stimulation. Most of the disruptors are chemical substances found in products like pesticides, insecticides, fungicides and other agricultural and industrial chemicals which lead to occupational toxicology or poisoning.
These chemicals can also passed through food chains in which they are magnified up the chain for example feeding on fish from contaminated waters. The effects of these chemicals can either be acute or chronic with consequences like low fertility in both males and female, changes in hormonal levels, improper immune system functions and cancers like pituitary, thymus, adrenocortical and parathyroid. Exposure to the chemical substances may result in adverse irreversible effects especially at young age which persists to adulthood.
These chemicals find their way in to the body mainly through food which accounts for about 90 % of all DDT and PCB for example fish and other food products were found to contain polybrominated diphenyl ethers (PBDE) in a research conducted on food substances from some groceries in USA. PBDE interferes with thyroid hormonal balance leading to learning disabilities especially in young persons. These chemicals also interfere with the hormones responsible for fetal growth which after a long time leads to reduced immunity.
Other chemicals include phthalates which is mostly found in plastics like the ones used to manufacture toys, cosmetics and air fresheners. Phthalates affects the development of reproductive systems in infants by altering the normal sperm production and testosterone leading to delayed puberty. Due to these adverse effects the use of certain chemicals has been banned in most countries in the world for example Dichloro-Diphenyl-Trihloroethane (DDT) and Polychlorinated Biphenyl (PCB).
The endocrine disruptors are regulated in many nations by forming organizations for example food, drug and cosmetic act, safe drinking water act, clean air act, toxic substances control act and many others with a common objective of identifying, preventing and reducing pollution which have effects on humans and the environment. Another important organization is endocrine disruptor screening program that was set up to test chemicals, their structure and possible disruptor elements in these substances.
This is done using in vitro tests by determining whether the substance interacts with estrogen and androgen receptors. If a substance binds to these receptors then that substance is a potential endocrine disruptor. Drinking water from rivers has potential disruptors for instance alkyphenols (AP) and alkyphenol ethoxylates (APEs). APE is not degraded fully during water treatment and easily dissolves in water increasing the possibility of easily getting to human body causing adverse effects.