164
The term “endocrine disruptor”, now part of the scientific and popular common
language, raises concerns but also questions from practitioners faced with patient
questions about environmental causes of their illnesses, or occupational physicians
as part of the chemical risk prevention. The concept has now been extended to other
hormonal systems than sex steroids, and his definition is still not unanimous in the
scientific community [37].
10.4.2 The Testicular Dysgenesis Syndrome
In recent decades, concerns about changes in the environment and their possible
consequences for human and animal reproduction have increased. Several studies
have described a gradual decline in the production and quality of sperm over time in
humans in Western countries. Indeed, in Northern Europe as well as in the United
States, the number of spermatozoa per ejaculate has decreased by about 1% per year
since the 1940s until today [38–43]. A very recent study conducted in France on a
cohort of 26,609 men reports an even greater decrease in the number of spermatozoa and sperm quality [44].
In addition, an increase in the frequency of testicular cancers in Europe has also
been described. This frequency increases regularly from 2 to 4% per year in adult
men in the 25 to 40 age group The increase in testicular cancers is also described in
the American population between 1975 and 2004 [45]. On the other hand, an
increase in the incidence of two congenital abnormalities of the external genitalia
has also been reported: cryptorchidism, or absence of testicular descent [46] and
hypospadias, which is a morphological alteration of the urethra [47]. These correlations have allowed Sharpe and Skakkebaek to hypothesize that these different
abnormalities are the symptomatic manifestations of the same syndrome, the TDS
(testicular dysgenesis syndrome) which is caused by defects in testicular development during fetal life and may also be caused by genetic, environmental and lifestyle factors, or by a combination of these [48, 49] (Fig. 10.3).
10.5 Evaluation of the Male Reproductive Toxicity
of a Substance
10.5.1 Understanding the REACH Regulation
REACH is a regulation of the European Union. It stands for Registration, Evaluation,
Authorisation and Restriction of Chemicals. It entered into force on June 1st, 2007
and was adopted to improve the protection of human health and the environment
from the risks that can be posed by chemicals, while enhancing the competitiveness
of the chemicals industry in the European Union. This regulation also promotes
C. Pineau
The term “endocrine disruptor”, now part of the scientific and popular common
language, raises concerns but also questions from practitioners faced with patient
questions about environmental causes of their illnesses, or occupational physicians
as part of the chemical risk prevention. The concept has now been extended to other
hormonal systems than sex steroids, and his definition is still not unanimous in the
scientific community [37].
10.4.2 The Testicular Dysgenesis Syndrome
In recent decades, concerns about changes in the environment and their possible
consequences for human and animal reproduction have increased. Several studies
have described a gradual decline in the production and quality of sperm over time in
humans in Western countries. Indeed, in Northern Europe as well as in the United
States, the number of spermatozoa per ejaculate has decreased by about 1% per year
since the 1940s until today [38–43]. A very recent study conducted in France on a
cohort of 26,609 men reports an even greater decrease in the number of spermatozoa and sperm quality [44].
In addition, an increase in the frequency of testicular cancers in Europe has also
been described. This frequency increases regularly from 2 to 4% per year in adult
men in the 25 to 40 age group The increase in testicular cancers is also described in
the American population between 1975 and 2004 [45]. On the other hand, an
increase in the incidence of two congenital abnormalities of the external genitalia
has also been reported: cryptorchidism, or absence of testicular descent [46] and
hypospadias, which is a morphological alteration of the urethra [47]. These correlations have allowed Sharpe and Skakkebaek to hypothesize that these different
abnormalities are the symptomatic manifestations of the same syndrome, the TDS
(testicular dysgenesis syndrome) which is caused by defects in testicular development during fetal life and may also be caused by genetic, environmental and lifestyle factors, or by a combination of these [48, 49] (Fig. 10.3).
10.5 Evaluation of the Male Reproductive Toxicity
of a Substance
10.5.1 Understanding the REACH Regulation
REACH is a regulation of the European Union. It stands for Registration, Evaluation,
Authorisation and Restriction of Chemicals. It entered into force on June 1st, 2007
and was adopted to improve the protection of human health and the environment
from the risks that can be posed by chemicals, while enhancing the competitiveness
of the chemicals industry in the European Union. This regulation also promotes
C. Pineau