Two chemicals found in household products and food could harm male fertility in both dogs and people, U.K. researchers say.
The chemicals are the plasticizer DEHP — used in products such as carpets, flooring, upholstery, clothes, wires and toys — and the industrial chemical polychlorinated biphenyl 153 (PCB153). Even though it is banned worldwide, PCB153 is still widely present in the environment, including food.
For this study, researchers from the University of Nottingham conducted laboratory tests with sperm from men and dogs. Their tests revealed that levels of the two chemicals consistent with environmental exposure had the same damaging effects on sperm in both species — reduced sperm motility and increased fragmentation of DNA.
Previous studies have reported a 50 percent decline in human sperm quality worldwide in the past 80 years. Another study by the same U.K. team found a similar decline in domestic dogs, pointing to the possibility that chemicals present in the home could be a factor.
“This new study supports our theory that the domestic dog is indeed a ‘sentinel’ or mirror for human male reproductive decline, and our findings suggest that man-made chemicals that have been widely used in the home and working environment may be responsible for the fall in sperm quality reported in both man and dog that share the same environment,” study leader Richard Lea said in a university news release.
Lea is an associate professor and reader in reproductive biology at Nottingham’s School of Veterinary Medicine and Science.
“Our previous study in dogs showed that the chemical pollutants found in the sperm of adult dogs, and in some pet foods, had a detrimental effect on sperm function at the concentrations previously found in the male reproductive tract,” he said.
Lea added that the new study is the first to test the effect of DEHP and PCB153 on both dog and human sperm in the lab, in the same concentrations found in real life.
Gary England is dean of the university’s School of Veterinary Medicine and Science.
“Since environmental pollutants largely reflect a Western way of life such as the effects of industry, the chemicals present in the environment are likely to depend on the location,” he said in the news release. “An important area of future study is to determine how the region in which we live may effect sperm quality in both man and dog.”
The study was recently published in the journal Scientific Reports.
What is male infertility?
Infertility is the state of being unable to get pregnant. According to the National Institute of Child Health and Human Development, about 15% of couples are infertile after they have been trying to get pregnant for one year with no success.
Symptoms of male infertility
Typically, men do not have symptoms of infertility. Contact your doctor if you have tried to get pregnant for one year without the use of birth control and your partner has not gotten pregnant.
What causes male infertility?
The most common cause of male infertility is a varicocele. It occurs when you have enlarged veins in your scrotum. This is the skin sac that hangs behind your penis. A varicocele can occur on one or both sides. It makes the inside of your scrotum warmer, which reduces sperm production. Age can also be a factor. Fertility starts to decrease in men after age 35.
Other causes include:
a blockage in your reproductive system
low sperm count
sperm that are abnormally shaped or that don’t move correctly
certain health conditions, such as cancer
an infection or sexually transmitted disease (STD)
Sometimes the cause of male infertility is unknown. In these cases, it may be genetic, lifestyle, or environmental factors.
How is male infertility diagnosed?
For most men, a doctor can help find the cause of infertility. It may be a related health problem. Your doctor will do an exam and review your medical history. A semen analysis will tell your sperm count and quality. These are important aspects of fertility. Another test your doctor may do is a check of your hormone levels.
Can male infertility be prevented or avoided?
You cannot always prevent male infertility. However, there are factors that can affect this condition that you should avoid. These include:
overheated testicles, which can kill sperm. This can occur from frequent hot tub use or wearing underwear or pants that are too tight.
Male infertility treatment
More than half of male infertility cases can be corrected. Treatment options depend on the root cause. Medicine can improve hormone levels or erectile dysfunction. Surgery can help correct physical problems, such as a varicocele. It also can repair blockages or other damage. Surgery often is minor and done as an outpatient procedure.
Living with male infertility
There is not always a cure for male infertility. Treatment may not help or a couple still might not be able to get pregnant through sexual intercourse. In this case, your doctor may suggest other options to make a baby. Assisted reproductive technology (ART) treatments can include:
Intrauterine insemination (IUI). A man’s sperm is collected and inserted into the woman’s uterus. This procedure is done at the time of ovulation.
In vitro fertilization (IVF). This technique is more complex. A man’s sperm and a woman’s egg are fertilized in the lab. Then it is implanted back in the woman’s uterus.
ART treatments often are effective, but are not a guarantee. If a man cannot produce sperm, a couple may look for a sperm donor. Some people consider adoption in place of ART or if ART is not successful.
Questions to ask your doctor
If my partner or I are over the age of 35, do we have to wait until we haven’t been successful for a year before being tested for infertility?
What is the recovery time for surgery to treat male infertility?
Will treatment make it possible for us to have a baby?
If treatment doesn’t work, what are our other options?