Study points to anesthetic gases, radiation and pesticides as probable causes
THURSDAY, April 3 (HealthDay News) -- Women veterinarians have double the risk of miscarriage, apparently the result of being exposed to anesthetic gases, radiation and pesticides in their line of work, a new study found.
Not only do veterinarians need to be fully aware of the risks, but veterinary offices and labs need to be managed better, the researchers said.
"We found that not all practices complied with safety guidelines," said study lead author Adeleh Shirangi, honorary research associate in the department of epidemiology and public health at Imperial College London, England. "Lead shields, protective thyroid collars and lead glasses are examples of established protective equipment which are not frequently used by veterinarians."
Dr. Richard Jones, assistant professor of obstetrics and gynecology at Texas A&M Health Science Center College of Medicine, said: "The good thing about this study is that it basically confirms and reminds us of what we already knew about exposures. This makes a valuable contribution to the evidence already in the U.S. recommending limitations of exposure of women of childbearing age to anesthetic gases, radiation and pesticides."
Jones, who's also director of the maternal fetal medicine program at Scott & White Hospital in Temple, Texas, added that the information in the new study didn't come as a surprise to him. Already in hospitals, many procedures are in place to protect personnel from the harmful effects of radiation and other exposures. The veterinary world, however, is not as rigorously regulated, he said.
The study was published online April 3 in the journal Occupational and Environmental Medicine.
Previous research has linked miscarriages to exposure to anesthetic gases, radiation and pesticides during pregnancy.
One study by the same authors behind the new research found anesthetic gas exposure during surgeries in 92 percent of small-animal practices and 42 percent of large-animal practices. Twenty-two percent of women veterinarians in small practices and 34 percent of women in mixed practices (both large and small animals) did not have anesthetic gas scavengers, which trap and remove extra gases.
Exposure to pesticides was seen in 54 percent of mixed-animal practices, 47 percent of small-animal practices and 17 percent of large-animal practices, the researchers said.
Exposure to X-rays was found in 90 percent of small- and mixed-animal practices, compared with 37 percent of large-animal practices. Fifty-six percent of women vets reported having to physically restrain animals while taking X-rays, while only one in five used film holders and lead screens to protect themselves.
For the new study, Shirangi and her colleagues looked at women participating in the Health Risks of Australian Veterinarians study. All people who had graduated from Australian veterinary schools from 1960 to 2000 were sent questionnaires. Only women who were pregnant or became pregnant while employed and were working only in a clinical practice were analyzed. Of 1,355 pregnancies, 940 were included in the final analysis.
The researchers found an almost 2.5-fold increase in the risk of miscarriage in women exposed to unscavenged anesthetic gases (those not filtered out) for more than one hour a week.
Female veterinarians who reported performing more than five X-rays a week had almost double the risk of miscarriage, as did those who used pesticides.
According to Shirangi, the same chemicals are used in veterinary offices around the world.
There appeared to be no link between number of hours worked and miscarriage, although the study authors aren't ruling out such an association.
"Properly ventilating the workplace (using scavenging systems), minimizing the amount of exposure through radiation protection devices such as masks, shoes, lead aprons, thyroid protectors, lead gloves, lead screens or film holders, is of vital importance," Shirangi said.
In addition, she said, "All anesthesia machines and their scavenging systems should be checked with each use and maintained regularly by trained technicians. Each institution should provide a system whereby an employee can report a work-related health problem."
For more on a healthy pregnancy, visit the March of Dimes.
SOURCES: Adeleh Shirangi, Ph.D., honorary research associate, department of epidemiology and public health, Imperial College London, England; Richard Jones, M.D., assistant professor of obstetrics and gynecology, Texas A&M Health Science Center College of Medicine, and director, maternal fetal medicine program, Scott & White Hospital, Temple, Texas; April 3, 2008, Occupational and Environmental Medicine, online
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