The impact of endocrine disruptors on health

Introduction
What are endocrine disruptors?
How can endocrine disruptors enter the human body?
What are the health effects of endocrine disruptors?
Effects on the reproductive system
Effects on the adrenal gland
Effects on the thyroid gland
Effects on the pituitary gland
Endocrine disruptors and endocrine malignancies
References
More information


Endocrine disruptors are natural or artificial chemicals that interfere with the body’s endocrine system. The endocrine system includes a number of glands and organs that synthesize, store and secrete hormones. Endocrine disruptors can cause a variety of health conditions, including developmental disorders, reproductive, neurological, and immunological disorders.

Image Credit: Olivier Le Moal / Shutterstock.com

What are endocrine disruptors?

More than 1,000 chemicals have been identified in the environment with powerful abilities to disrupt the endocrine system. These include pesticides, fungicides, industrial chemicals, plasticizers, nonylphenols, metals, pharmaceutical agents and phytoestrogens.

According to the United States Environmental Protection Agency (EPA), any exogenous chemical that can affect the synthesis, transport, metabolism, and elimination of endogenous hormones can be identified as an endocrine disruptor.

Based on the origin, endocrine disruptors can be categorized as industrial (polychlorinated biphenyls), agricultural (pesticides), pharmaceutical (parabens) and household (bisphenol A). In addition, heavy metals, including lead, mercury, cadmium and arsenic, can be considered endocrine disruptors.

How can endocrine disruptors enter the human body?

Endocrine disruptors enter the human body mainly through ingestion (ingestion of food / water), inhalation or direct exposure of the skin. Most of these chemicals are lipophilic and thus accumulate in adipose tissue. This leads to a very long half-life of these chemicals in the body.

Exposure time is an important parameter in determining the exact effect of endocrine disruptors in humans. In most cases, the effects develop gradually and manifest themselves in later stages of life. For some people, these chemicals do not cause any obvious effects.

What are the health effects of endocrine disruptors?

Endocrine disruptors can affect the functioning of the endocrine system by altering normal hormone levels, mimicking the functions of endogenous hormones, or altering hormone production.

Endocrine disruptors mimic the functions of endogenous hormones by directly binding and activating a wide range of hormone receptors, including estrogen receptors, androgen receptors, glucocorticoid receptors, thyroid hormone receptors, and the retinoid X receptor.

Image credit: Pikovit / Shutterstock.com

Image credit: Pikovit / Shutterstock.com

Effects on the reproductive system

Because most endocrine disruptors are able to mimic sex hormones, the greatest adverse effects have been observed on the reproductive system. by interfering with sex steroid hormones, endocrine disruptors can significantly affect fetal development. Among the various destroyers, synthetic estrogens, phytoestrogens, pesticides, plasticizers and industrial chemicals exhibit strong antiandrogenic and weak estrogenic properties.

During ovarian development in animals, endocrine disruptors have been shown to interfere with follicle formation, meiosis, and vitality. During the early postnatal period, these chemicals can alter the genetic transcription of somatic cells, which in turn can delay the onset of puberty.

Exposure to endocrine disruptors can cause fertility problems in both men and women. Studies have linked exposure to endocrine disruptors to testicular malnutrition, polycystic ovaries, testicular dysgenesis syndrome, and hormone-sensitive ovarian and testicular cancer.

Effects on the adrenal gland

High blood flow and high levels of fatty acids (lipophilic) make the adrenal gland a suitable target for endocrine disruptors. Studies examining the effect of these chemicals on the hypothalamic-pituitary-adrenal axis highlight the possibility of impaired synthesis and metabolism of steroid hormones. In particular, endocrine disruptors have been shown to impair adrenal steroidogenesis by modulating the functions of aromatase, 5-α reductase and hydroxysteroid dehydrogenase.

Effects on the thyroid gland

Some endocrine disruptors, including perchlorate and thiocyanate, have been shown to affect iodine absorption by inhibiting the sodium iodide transport channel. This leads to impaired biosynthesis of thyroid hormones.

Common sources of perchlorate include explosives, airbags, fertilizers and some foods (milk, eggs, fruits and vegetables). Cigarette smoke is a powerful source of thiocyanate. A study involving puberty participants found that exposure to perchlorate, thiocyanate and nitrates caused a significant reduction in free thyroxine levels.

Effects on the pituitary gland

Many endocrine disruptors act directly on the diencephalic system, mimicking the functions of neurotransmitters. This subsequently affects the hypothalamic-pituitary-gonadal axis and causes a number of consequences, including delayed onset of puberty and disruption of the circadian system.

Some endocrine disruptors, such as estrogenic chemicals, have been shown to increase the synthesis and secretion of pituitary hormones, including prolactin and thyroid-stimulating hormone (TSH). This subsequently increases the risk of breast and thyroid cancer. In addition, there is evidence to suggest a role for estrogenic chemicals in the development and progression of pituitary cancer.

Endocrine disruptors and endocrine malignancies

There is ample evidence to suggest that endocrine disruptors increase the risk of testicular, prostate, thyroid and breast cancer. These endocrine disruptors include fungicides, pesticides, polybrominated diphenylethers (PDBE), organochlorides, polychlorinated biphenyl (PCBs), dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyl dichloroethylene (DDE), arsenic and cadmium.

Occupational exposure to pesticides and biocides is associated with a significantly increased risk of thyroid cancer. The risk is more pronounced in men. Similarly, exposure to PCBs, dioxins, cadmium, phytoestrogens, diethylstilbestrol (DES), furans, ethylene oxide has been shown to increase the risk of breast cancer. With regard to prostate cancer, arsenic, cadmium, PCBs and pesticides have been identified as possible participants.

Endocrine disruptors are everywhere and affect everyone: from hormone-altering chemicals

References

More information

Leave a Comment

Your email address will not be published.