Sexual Differentiation Disorders
X and Y chromosome are necessary for testicular development. Two x chromosomes are necessary for complete ovarian function. Male sexual differentiation originates from an undifferentiated gonad that is derived from epithelium, mesenchyme, and germ cells. With the presence of testicular determining factor (TDF), gives rise to Leydig cells, Sertoli cells, seminiferous tubules and spermatogonia. Testes are formed at seven weeks. The conversion of testosterone to dihydroxytestorone by 5 alpha reductase and its binding to androgen receptors cause the external genital masculinization.
In the female the undifferentiated gonad gives rise to follicles, granulose cells, theca cells, and ova. Ovarian development occurs in the thirteenth to sixteenth week of gestation. Lack of dihydroxy testosterone results in the maintenance of female genitalia. Both in females and males the external genitalia arise from the urogenital tubercle, urogenital swelling and urogenital folds.
Hypospadias, a developmental anomaly in the male in which the urethra opens on the bottom of the penis, and cryptorchidism (failure of the testes to descend) have been linked to prenatal estrogen exposure in animal models. Pesticide use on farms and house hold gardens have been shown to possess estrogenic and other hormone-disrupting effects. Studies have shown that an increased risk of urogenital malformations have been found in the sons of pesticide appliers. A significant increased risk of cryptorchidism was found among sons of women working in conventional gardens that used pesticides in a study of 6, 177 cases of cryptorchidism and 23, 273 controls. The study was performed in Scandinavia.67
Pregnant women living close to farms where pesticides are sprayed on fields may have an increased risk of having fetus die to birth defects. Mothers should to their best ability avoid all pesticides and chemicals during pregnancy.68 A detoxification before pregnancy is recommended. ADD, asthma, and allergies have been linked to pesticide exposure in foods. The importance of eating organic foods cannot be overemphasized.
Premature Puberty
The maturation of the hypothalamic-pituitary axis initiates puberty. Gonadotropin- releasing factor is secreted from the hypothalamus and tells the pituitary gland to secrete leuteinizing hormone (LH) and follicle stimulating hormone (FSH). These hormones stimulate gonads to enlarge and to secrete sex steroids that circulate and initiate the development of secondary sex characteristics.
Organic pollutants, including pesticides and some plasticizers, can disrupt normal sexual development. DEHP is a phthalic ester that is found in food, water and medical equipment from contact with plastic containers, plastic wrappings and containers, plastic toys and pacifiers. The daily consumption of DEHP in the United States is 5.8 mg, and 2.1 mg in Japan. These high levels have been linked to the cause of premature puberty.69
In the United States, normal puberty occurs between 9 and 14 years. However puberty is occurring earlier and earlier due to chemical exposure.
