They also said the rate of decline is not slowing. Both findings -- in a meta-analysis bringing together various studies -- pointed to a potential decline in male health and fertility. The analysis did not explore reasons for the decline, but researchers said falling sperm counts have previously been linked to various factors such as exposure to certain chemicals and pesticides, smoking, stress and obesity. This suggests measures of sperm quality may reflect the impact of modern living on male health and act as a "canary in the coal mine" signaling broader health risks, they said. Studies have reported declines in sperm count since the early s, but many of those have been questioned because they did not account for potentially major confounding factors such as age, sexual activity and the types of men involved. Working with a team of researchers in the United States, Brazil, Denmark, Israel and Spain, Levine screened and brought together the findings of sperm count studies from to and then conducted a so-called meta-regression analysis.
Sperm counts are on the decline – could plastics be to blame? | US news | The Guardian
A recent study that tested both men and dogs added to concerns that chemicals in the environment are damaging the quality and quantity of sperm. Make a contribution. Fri 24 May S urprising new research into dog sperm has reproductive biologists concerned about the fate of their own species. In a March study , scientists at Nottingham University found that two chemicals common in home environments damage the quality of sperm in both men and dogs. The culprits implicated are diethylhexyl phthalate DEHP , used to make new plastics more pliable, and polychlorinated biphenyl PCB , found in older plastics and electrical equipment. Companies stopped producing PCBs in the late s due to their health risks — including a possible increased risk of cancer, hormone disruption, liver damage and behavioral or cognitive deficits in children exposed to the chemical in utero — but the chemical persists in the environment.
Are Sperm Counts Truly Declining, And, If So, What Is Likely To Be The Cause?
The shock conclusion of a study 20 years ago indicated that sperm counts had halved. But a closer look at the evidence then and now paints a much more complex story. People will probably have plenty of theories as to why this is happening — perhaps because of herbicides, pesticides, or oestrogens in the water from so many women being on the pill. Or there are theories based on lifestyle — for instance, men are taking less exercise, eating more fast food and getting fatter.
Low sperm count means that the fluid semen you ejaculate during an orgasm contains fewer sperm than normal. A low sperm count is also called oligospermia ol-ih-go-SPUR-me-uh. A complete absence of sperm is called azoospermia. Your sperm count is considered lower than normal if you have fewer than 15 million sperm per milliliter of semen. Having a low sperm count decreases the odds that one of your sperm will fertilize your partner's egg, resulting in pregnancy.