J., J. Larsen, P. Christiansen, A. Giwercman, P Grandjean, L.J. Guillette
Jr., B. Jegou, T.K. Jensen, P. Jouannet, N. Keiding, H. Leffers, J.A.
McLachlan, O. Meyer, J. Muller, E. Rajpert-De Meyts, Thomas Scheike,
R. Sharpe, J. Sumpter, and N.E. Skakkebaek. 1996.Male Reproductive
Health and Environmental Xenoestrogens. Environmental
Health Perspectives 104(Suppl 4):741-803
paper is the result of a one-week workshop convened at the request
of the Danish Environmental Protection Agency in Copenhagen in January
et al. review the literature on changes in male reproductive
health. "The growing number of reports demonstrating that common
environmental contaminants and natural factors possess estrogenic
activity presents the working hypothesis that the adverse trends
in male reproductive health may be, at least in part, associated
with exposure to estrogenic or other hormonally-active (e.g., antiandrogenic)
environmental chemicals during fetal and childhood development."
et al. also review the literature on environmental chemicals
with known estrogenic effects (as of January 1995), sources of human
exposure and phytoestrogens.
count: the cautious general conclusion was that a real
decline occurred during the 50-year period (examined by Carlsen
et al.). "The reason remains unknown, but further examination
may provide important clues to the etiology of decreasing sperm
cancer: This is now the most common malignancy of young
men in many countries. Increases in incidence are demonstrated
by data from cancer registries in England, Wales, Scotland, the
Nordic and Baltic countries, Australia, New Zealand and the United
States. "The observed increase has been approximately 2 to 4%
per annum in men under 50 years of age."
A series of studies suggest general increases in cryptorchidism
but differences among the studies make it difficult to reach a
firm conclusion. "From these three large studies, one can conclude
that there has been a significant increase in the incidence of
cryptorchidism in England, but the incidence in the racially and
ethnically mixed population of New York is similar to that reported
in the 1950s in England."
"Birth data from several reports have indicated a substantial
increase in prevalence of hypospadias." As with cryptorchidism,
variations in methodology make general conclusions difficult to
reach, but increases have been noted in countries where longitudinal
data have been studies. The increase has been reported primarily
in England, Wales, Hungary, Sweden, Norway and Denmark. No increases
have been reported from Finland, Spain, New Zealand, Australia
R, H-O Adami, M Mohner, W Zatonski, H Storm, Anders Ekhom, S Tretli,
L Teppo, O Akre and T Hakulinen. 1996. Increase in testicular cancer
incidence in six European countries. Journal of the National Cancer
incidence of testicular cancer has increased rapidly in virtually
all countries studied. Bergstrom et al. examined cancer registries
from Denmark, Norway, Sweden, the former East Germany, Finland and
Poland to determine whether the increase in testicular cancer is related
to year of birth. They found that while there was little change in
testicular cancer risk for men born between 1880 and 1920, the risk
began to rise thereafter. The rate of increased varied among the countries
studied. From 1905 to 1965, it increased by a factor of 3.9x in Sweden
to 11.4x in East Germany. "Our investigation shows unequivocally that
birth cohort is a more important determinant of testicular cancer
risk than is time period."
R, M García-Martín, M Nogueras-Ocaña, J de Dios Luna-del-Castillo,
M Espigares García, N Olea, P Lardelli-Claret. 1996. Exposure to
Pesticides and Cryptorchidism: Geographical Evidence of a Possible
Health Perspectives 104(10):1090-1095 .
with other disorders of the male reproductive tract, data suggest
that cryptorchidism (undescended testes) has increased in recent decades,
at least in some regions of the world. Garcia-Rodriguez et al. carried
out an epidemiological study of the frequency of cryptorchidism in
boys aged 1-16 in relation to the geography of pesticide use in the
province of Granada, Spain.
findings "are compatible with a hypothetical association between
exposure to hormone-disrupting chemicals and the induction of cryptorchidism."
They caution, however, that methodological limitations "make it
necessary to evaluate the results with caution."
JM, TW Hensle and H Fisch. 2000. Increasing risk of developing
testicular cancer by birth cohort in the United States. Dialogues
in Pediatric Urology 23(1): 7-8.
McKiernan et al. analyze 12,099 incidents of testicular cancer in
the SEER database between 1973 and 1995. They report a steady increase
in the rate of testicular cancer in the US over this 23 yr time period:
from 3.61 per 100,000 to 5.44, or 51%. They also find that the age
of peak incidence has decreased and report this as a birth cohort
effect. This particularly interesting because "a birth cohort
phenomenon occurs when a cohort, or study group, share a common time
period of birth and a similar risk of developing a particular disease.
Unlike most other cancers, testicular cancer, with a peak incidence
in the third decade of life, suggests a latency period that involves
some pre or postnatal stimulatory event that influences subsequent
tumor development. The widespread observation of a birth cohort correlation
for testicular cancer suggests that early or prolonged exposure to
some carcinogenic stimuli might be required for the subsequent development
of testicular cancer. "