it's all about sex

[Neil Tangri <ntangri@essential.org>]

Pesticides could make men less fertile

                UK: August 7, 1999

                LONDON - Regular exposure to pesticides could make
                men less fertile, doctors said on Friday. 

                Researchers from Wageningen Agricultural University in the
                Netherlands studied how exposure to pesticides affected
                the ability of the sperm to fertilise eggs, surveying 836
                couples who had sought in-vitro fertilisation (IVF) since
                1991.

                "Our results are the first to suggest that paternal pesticide
                exposure decreases the sperm fertilising ability in vitro,"
the
                researchers told the Lancet medical journal.

                "Fertilisation rates were significantly decreased for couples
                with paternal pesticide exposure."

                The men taking part in the survey were asked a series of
                questions to determine how exposed they were to
                pesticides and other hazardous substances.

                The researchers found rates of conception for couples with
                male partners who were exposed to pesticides in their jobs
                were significantly lower.

                But they said they could not isolate which chemical was
                the problem. "Because most individuals were exposed to
                multiple pesticides with various active ingredients, it is
                impossible to draw conclusions as to which chemical may
                be responsible for that effect," they wrote.

                The team adjusted the results for paternal or maternal
                smoking habits, caffeine use, alcohol consumption and
                other occupational exposures but it had little effect on the
                conclusions. 

                REUTERS NEWS SERVICE 



Toxic chemicals could lead to low
                female sex drive

                UK: August 7, 1999

                LONDON - Exposure to toxic chemicals while in the
                womb could explain low sex drives in women, New
                Scientist magazine said on Wednesday. 

                The magazine cited a study by zoologists at Michigan
                State University which said female rats that were exposed
                to PCBs (polychlorinated biphenyls) in the womb seemed
                reluctant to mate as adults.

                "This raises the possibility that similar chemical
                contaminants may cause low sex drives in women," it said.

                PCBs are toxic chemicals which may indicate the presence
                of cancer-causing dioxins. Belgium's recent dioxin food
                scare was triggered when tests revealed the presence of
                PCBs in animal feeds.

                Zoologists Yu-Wen Chung and Lynwood Clemens tested
                the effects on rats of two commercial PCBs, Aroclor 1221
                and 1254.

                They injected 40 pregnant rats with either pure sesame oil
                or a mixture of oil and the PCBs at different points during
                and after pregnancy. They then studied the behaviour of the
                female offspring.

                "Chung suspects that during a crucial phase of
                development, the oestrogen-mimicking A1221
                "defeminises" the rat fetuses. She says women's sex drives
                could also be affected by PCB exposure in the womb," New
                Scientist said.

                "It's possible. Pregnancy is the critical period," Chung told
                the magazine.

                New Scientist said PCBs were once widely used in the
                production of pesticides, lubricants and plastics.

                Their use was banned in many countries after it became
                clear that some PCBs mimic hormones but there is strong
                evidence that they are still widespread in the environment, it
                said.

                "Female rats normally adopt a stereotypical posture when
                copulating, raising their back and hindquarters to help the
                male mate," Chung told the magazine.

                But rats injected with A1221 did not do this as often as rats
                exposed to A1254 or those not exposed to either PCB.

                A second test paired female and large male rats in a cage
                with two compartments. If the females did not feel like
                mating, they could escape into the second chamber
                through a hole too small for the larger males.

                Females exposed to A1221 left the males more often and
                took longer to return after each copulation attempt by the
                males.

                But Paul Stewart, a psychologist at the State University of
                New York, told New Scientist that PCBs in humans were
                usually at much lower levels than those used in the tests.

                "He also questions whether PCBs were lowering the rats'
                overall levels of activity rather than just their sex
drive," the
                magazine said. 

                REUTERS NEWS SERVICE

--

Neil TANGRI