Environmental FactorsAnd Reproductive Health:

“Effects of Radiation”

Satarupa DebLife Science & BioinformaticsAssam University

Definition Of Reproductive HealthThe World Health Organization's (WHO) definition of health is: “A state of complete physical, mental and social well-being, good reproductive health, or sexual health/hygiene, which address the reproductive processes, functions and system at all stages of life”.

 Reproductive health implies that:

“People are able to have a responsible, satisfying and safer sex life and that they have the capability to reproduce and the freedom to decide if, when and how often to do so”. 

“ Radiation”In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium.Radiation is often categorized as:- ionizing or non-ionizing depending on the energy of the radiated particle.

Ionizing radiation is radiation that carries enough energy to free electrons from atoms or molecules, thereby ionizing them. Ionizing radiation is made up of energetic subatomic particles, ions or atoms moving at relativistic speeds.

Non-ionizing radiation refers to any type of electromagnetic radiation that does not carry enough energy per quantum (photon energy) to ionize atoms. Instead of producing charged ions when passing through matter, the electromagnetic radiation has sufficient energy only for excitation, the movement of an electron to a higher energy state.

 This is an important distinction due to the large difference in harmfulness to living organisms.

Gamma rays, X-rays, and the higher ultraviolet part of the electromagnetic spectrum are ionizing, whereas the lower ultraviolet part of the electromagnetic spectrum, visible light (including nearly all types of laser light), infrared, microwaves, and radio waves are considered non-ionizing radiation.

Sources Of Radiation ExposurePeople are exposed to radiation in mainly two modes: 

From radiation sources outside the body (external exposure).From radioactive substances that are inhaled or ingested into the body (internal exposure).

EXTERNAL EXPOSURE:

Occupational sources.

Medical treatments.

Nuclear weapons, reactors or accidents.

Devices or instruments which work on EMR.

INTERNAL EXPOSURE:

Intake of radioactive material inside the body.

Irradiation of the deposited and surrounding organs and tissues by the rays emitted by radioactive materials.

Negative Effects Of Radiation

In Both Males & Females

 Irradiation to the central nervous system may affect the timing of the onset of puberty, result in hyperprolactinemia, or cause gonadotropin deficiency if the hypothalamic-pituitary axis is involved in the radiation field. 

In both male and female, and the elusive factors of radiation-induced teratogenesis and cancer have been proven by various experiments.

The response of the reproductive system to the effects of irradiation varies with age of the individual, amount of tissue

exposed, as well as dosage of radiation.

In Males

INFERTILITY : The testicles are very sensitive to the effects of radiation. Radiation can reduce the number of sperm produced or damage sperm and affect their ability to function. Temporary or permanent infertility (inability to father a child) can occur because of radiation to the testicles.

ASPERMIA: Direct irradiation to the testis will, in lower doses, affect the germinal epithelium: doses of irradiation greater than 0.35 Gy cause aspermia, which may be reversible. The time taken for recovery increases with larger doses; however, with doses in excess of 2 Gy aspermia may be permanent. 

ERECTILE DYSFUNCTION: Radiation therapy to the pelvic area may cause erectile dysfunction (ED). ED means that a man can’t get or keep an erection. It happens because radiation lowers testosterone levels and can affect the arteries that carry blood to the penis, which is necessary for a firm erection.

LEYDIG CELL DYSFUNCTION: At higher radiation doses (> 15 Gy), Leydig cell function will also be affected. In addition to radiation dose, the vulnerability of the testis is dependent on the age at irradiation and the pubertal status of the male.

HYPOGONADISM: Another possible effect of cancer therapy on the male reproductive system is testosterone deficiency, also known as “hypogonadism”. This is the inability to produce enough of the male hormone, testosterone, and can result from damage to the Leydig cells or pituitary gland caused by radiation to the testicles or brain.

LOW HORMONAL LEVELS: Brain radiation can result in damage to the pituitary gland leading to low levels of the hormones (FSH and LH) needed to signal the testicles to make sperm and testosterone. Males with low levels of these hormones will need to take testosterone for the rest of their lives. However, it is sometimes possible for these men to attain fertility with the use of specialized hormone treatments. 

Effects of radiation on a boy’s (teenager) reproductive system

Boys who receive radiation to the pelvis may experience:

1. Lack of testosterone production.2. If the testicles are affected by radiation, they may not produce male sex

hormones.3. A lack of male sex hormones prevents the development of secondary sex

changes, such as growth of facial hair, development of heavy bones and muscles and lowering of the voice.

4. Low sperm count or temporary zero sperm count (azoospermia) with low doses of radiation to the testicles.5. Infertility with higher doses of radiation.

(Infertility may sometimes occur with low doses of radiation because testicular tissue is very sensitive to radiation).

Every effort is made to shield the testicles from radiation unless they contain cancer, but sometimes radiation scatter (radiation energy given off outside the treatment area) occurs and the testicles receive small amounts of radiation that will affect their functioning.

In an experiment, a few male rats were exposed with mobile phone continuously for 2 hours a day for 35 days. The findings showed a significant decrease in GPx and SOD of exposed rat sperm (p< 0.001), where as Catalase activity shows significant increase in sperm (p <0.001). Also observed the decrease in apoptosis and sperm count in exposed group. All datapsilas are expressed as mean plusmn standard deviation (SD) and were analyzed by analysis of variance (One way- ANOVA). Our results coveys that the regular use of mobile phone at domestic level can have negative impact on human health.

Additionally, sperm are electrically active cells and their exposure to cell phone electromagnetic waves and currents may affect their motility, morphology and even their count. Leaky plasma membranes, calcium depletion and oxidative stress are the postulated cellular mechanisms mediating the harmful effects of cell phones radiation on sperm and male fertility potentials.

Effects of cell phone radiation on male reproductive system

In Females Sterility: An ovarian dose of 4 Gy may cause a 30% incidence of sterility in young women, but 100% sterility in women over 40 years of age.

 Failure of uterine-expansion & premature labour: Pelvic irradiation may also have a profound effect on the uterus, with arrested growth in pre-pubertal girls, and failure of uterine expansion during pregnancy with subsequent miscarriages and premature labour.

Vaginal symptoms: Radiation therapy can cause:vaginal dryness, burning or itchingvaginal narrowing (stenosis) and scarring of the vaginafistulas (abnormal openings) between the vagina and the bladder.

Menopausal Problems: Loss of ovarian function can occur 2–3 weeks into treatment. Menstruation may stop and symptoms of menopause may occur in premenopausal women. The loss of ovarian function may be temporary or permanent.

Ovarian Dysfunction: Loss of ovarian function can occur 2–3 weeks into treatment. This can result in infertility (inability to become pregnant). The ovaries may stop producing eggs. Sometimes the ovaries will begin to produce eggs again once treatment ends and periods return to normal. If the ovaries don’t recover, infertility will be permanent.

Secondary (indirect) failure of the ovaries can occur as a result of radiation therapy to the brain. The pituitary gland, located in the center of the brain, regulates the production of two hormones (FSH and LH) needed for proper ovarian function. Radiation to the brain, especially at doses of 30 Gy (3000 cGy/rads) or higher can damage the pituitary gland, leading to low levels of these hormones.

Infertility. Infertility is the inability to achieve a pregnancy after at least one year of unprotected intercourse. In women, infertility occurs when the ovaries cannot produce eggs (ovarian failure), or when the reproductive organs are unable to sustain a pregnancy. 

Effects of radiation on a girl’s (teenager) reproductive system

Girls who receive radiation to the pelvis may experience:1. Lack of estrogen production:

If the ovaries are affected by radiation, they may not produce female sex hormones.

A lack of female sex hormones prevents the development of secondary sex changes, such as growth and maturation of the reproductive organs and the appearance of hair in the pubic area and underarms.

2. vaginal dryness, burning or itching3. narrowing or scarring of the vagina (vaginal stenosis)4. abnormal opening (fistula) between the bladder and vagina, or between the rectum and vagina, which may cause some leakage of urine or stool through the vagina.5. infertility – if the ovaries are exposed to high doses of radiation therapy.6. early menopause (by the age of 30) – if the ovaries have been damaged and don’t function properly.

Effects of cell phone radiation on female reproductive system:

Although we have considerable evidence that cell phone radiation damages sperm and is associated with male infertility, little attention has been paid to studying the effects of cell phone radiation on female infertility.In a 2013 review paper, Nazıroğlu and colleagues examined research on the effects of Wi-Fi and mobile phone radiation on reproductive signaling pathways. They reported that this radiation is related to "oxidative stress and overproduction of free oxygen radicals in female infertility."  The authors concluded that "the role of EMR from mobile phones and wireless devices in female and male fertility should be investigated.“

The results of some studies indicate that EMR induced endometriosis and inflammation and decreased the number of follicles in the ovarium or uterus of rats.

Positive Effects Of Radiation Radiation therapy kills cancer cells by damaging their DNA (the molecules inside cells that carry genetic information and pass it from one generation to the next). Radiation therapy can either damage DNA directly or create charged particles (free radicals) within the cells that can in turn damage the DNA.

Radioactive isotopes may be used for tracking biological molecules.