PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Male birth defect is weakly linked to pesticide exposure, Stanford-led study finds

2013-10-29
(Press-News.org) Contact information: Louis Bergeron
louisb3@stanford.edu
650-724-9175
Stanford University Medical Center
Male birth defect is weakly linked to pesticide exposure, Stanford-led study finds STANFORD, Calif. — A study of several hundred chemicals used in commercial pesticides has found only weak evidence that any of them are associated with a common birth defect in male infants.

The study, led by epidemiologists at the Stanford University School of Medicine, analyzed thousands of birth records and commercial pesticide application records for eight counties in California's heavily agricultural Central Valley. The researchers aimed to determine whether children were at increased risk of hypospadias if their mothers had lived in relatively close proximity to where pesticides were used while pregnant. Hypospadias is a genital malformation in which the urethral opening is on the underside of the penis rather than on the tip.

In the most detailed study of the largest data sets done to date, 292 individual chemicals and 57 groups of structurally similar chemicals were analyzed. Of those, the study identified 15 that had possible associations with hypospadias. But the researchers say further studies need to be done.

"We didn't see many chemicals that suggested an increased risk, and of those that did, most of them were infrequently used," said Suzan Carmichael, PhD, associate professor of pediatrics and lead author of the study to be published Oct. 28 in Pediatrics. "It is good news that such exposures are rare, but at the same time, when exposures are rare, it makes studies harder to do."

Approximately five of every 1,000 male infants are born with hypospadias, but the cause is usually unknown.

Most previous studies of pesticides and hypospadias focused on risks associated with occupations that involve the use of pesticides. Some studies have suggested slightly increased risks for infants whose mothers or fathers work around pesticides, but many studies suggest no association.

The researchers worked with data on births in the counties of Fresno, Kern, Kings, Madera, Merced, San Joaquin, Stanislaus and Tulare. The Central Valley, composed of the San Joaquin and Sacramento valleys, has one of the highest rates of pesticide usage in the nation.

The study population included all male infants born from 1991 to 2004 to mothers residing in any of the eight counties at the time of birth. The study sample comprised 690 cases of hypospadias, as well as 2,195 controls randomly selected for comparison.

The researchers considered pesticides used within 500 meters of the mother's residence during weeks one to 14 of each pregnancy. Urethral development typically occurs between weeks four and 14.

Hypospadias has a significant impact on public health, as it often requires surgical correction. Approximately 600,000 to 900,000 American males alive today were born with some degree of hypospadias. Even after correction, individuals may have impaired sexual function and emotional and social difficulties stemming from the condition.

"Any birth defect is concerning to parents, and a defect in the genital structure often causes special concern," said William Kennedy, MD, associate professor of urology at Stanford and associate chief of pediatric urology at Lucile Packard Children's Hospital.

"Parents are often reluctant to talk to anyone — even medical professionals — about the baby's condition," Kennedy added. "Fortunately, most corrective surgeries have positive outcomes."

In addition to exposures to individual chemicals and compounds, the researchers looked at exposure to multiple chemicals, but found no evidence to suggest that mothers' exposures to multiple pesticides put their babies at an increased risk of hypospadias.

"These results extend what we know, but at the end of the day they need to be replicated before we can really be sure whether there is, or is not, a real risk associated with these chemicals," said Gary Shaw, DrPH, professor of pediatrics at Stanford and a co-author of the study. Shaw, Kennedy and Carmichael are also members of the Child Health Research Institute at Stanford.

### Another Stanford co-author was Wei Yang, MS, research associate in pediatrics.

This work was done in partnership with colleagues at the California Environmental Health Tracking Program. The study was partially supported by grants from the National Institutes of Health (RO1 ES017060) and Centers for Disease Control Prevention.

The Stanford University School of Medicine consistently ranks among the nation's top medical schools, integrating research, medical education, patient care and community service. For more news about the school, please visit http://mednews.stanford.edu. The medical school is part of Stanford Medicine, which includes Stanford Hospital & Clinics and Lucile Packard Children's Hospital. For information about all three, please visit http://stanfordmedicine.org/about/news.html.

Print media contact: Louis Bergeron at (650) 724-9175 (louisb3@stanford.edu) Broadcast media contact: M.A. Malone at (650) 723-6912 (mamalone@stanford.edu)


ELSE PRESS RELEASES FROM THIS DATE:

Einstein researchers lead panels at NIH Aging and Chronic Disease Symposium on Geroscience

2013-10-29
Einstein researchers lead panels at NIH Aging and Chronic Disease Symposium on Geroscience October 29, 2013 – (BRONX, NY) – The National Institutes of Health (NIH) has chosen two leading aging researchers at Albert Einstein College of Medicine ...

Less toxic metabolites, more chemical product

2013-10-29
Less toxic metabolites, more chemical product Joint BioEnergy Institute researchers develop dynamic system for controlling toxic metabolites in engineered microbes The first dynamic regulatory system that prevents the build-up of toxic metabolites in ...

USC CTM releases report on Americans' media consumption

2013-10-29
USC CTM releases report on Americans' media consumption Predicts by 2015, average media consumption will be 15.5 hours a day per person Americans consume an enormous amount of media daily via television, radio, phone and computer. As you read this article ...

Canadian discoveries pivotal to the science of toxins and illness associated with E. coli

2013-10-29
Canadian discoveries pivotal to the science of toxins and illness associated with E. coli A tribute to Canadian researchers among the first to recognize the toxin-producing E. coli published today in the Canadian Journal of Microbiology Many ...

Sedentary behavior linked to recurrence of precancerous colorectal tumors

2013-10-29
Sedentary behavior linked to recurrence of precancerous colorectal tumors Men who spend the most time engaged in sedentary behaviors are at greatest risk for recurrence of colorectal adenomas, benign tumors that are known precursors ...

Estrogen protects women with NASH from severe liver fibrosis

2013-10-29
Estrogen protects women with NASH from severe liver fibrosis Severity of fibrosis similar in men and post-menopausal women New research suggests that estrogen protects women with nonalcoholic steatohepatitis (NASH) from severe liver fibrosis. According to the study published ...

Weight at time of diagnosis linked to prostate cancer mortality

2013-10-29
Weight at time of diagnosis linked to prostate cancer mortality Men who are overweight or obese when they are diagnosed with prostate cancer are more likely to die from the disease than men who are of healthy weight, according to a Kaiser Permanente study published ...

UCLA report urges new global policy effort to tackle crisis of plastic litter in oceans

2013-10-29
UCLA report urges new global policy effort to tackle crisis of plastic litter in oceans Plastic litter is one of the most significant problems facing the world's marine environments. Yet in the absence of a coordinated global strategy, an estimated ...

Scientists find that dolphin in Australian waters is a new species

2013-10-29
Scientists find that dolphin in Australian waters is a new species Study of humpback dolphin in Atlantic, Indian, and Pacific waters finds as-of-yet unnamed species A species of humpback dolphin previously unknown to science is swimming in the waters off northern ...

NASA sees Tropical Storm Raymond fading fast

2013-10-29
NASA sees Tropical Storm Raymond fading fast Satellite data showed some recent convective activity within Tropical Storm Raymond on Oct. 28 but southwesterly wind shear and cooler ocean temperatures are predicted by the National Hurricane Center to weaken the ...

LAST 30 PRESS RELEASES:

Fat may play an important role in brain metabolism

New study finds no lasting impact of pandemic pet ownership on human well-being

New insights on genetic damage of some chemotherapies could guide future treatments with less harmful side effects

Gut microbes could protect us from toxic ‘forever chemicals’

Novel modelling links sea ice loss to Antarctic ice shelf calving events

Scientists can tell how fast you're aging from a single brain scan

U.S. uterine cancer incidence and mortality rates expected to significantly increase by 2050

Public take the lead in discovery of new exploding star

What are they vaping? Study reveals alarming surge in adolescent vaping of THC, CBD, and synthetic cannabinoids

ECMWF - delivering forecasts over 10 times faster and cutting energy usage by 1000

Brazilian neuroscientist reveals how viral infections transform the brain through microscopic detective work

Turning social fragmentation into action through discovering relatedness

Cheese may really be giving you nightmares, scientists find

Study reveals most common medical emergencies in schools

Breathable yet protective: Next-gen medical textiles with micro/nano networks

Frequency-engineered MXene supercapacitors enable efficient pulse charging in TENG–SC hybrid systems

Developed an AI-based classification system for facial pigmented lesions

Achieving 20% efficiency in halogen-free organic solar cells via isomeric additive-mediated sequential processing

New book Terraglossia reclaims language, Country and culture

The most effective diabetes drugs don't reach enough patients yet

Breast cancer risk in younger women may be influenced by hormone therapy

Strategies for staying smoke-free after rehab

Commentary questions the potential benefit of levothyroxine treatment of mild hypothyroidism during pregnancy

Study projects over 14 million preventable deaths by 2030 if USAID defunding continues

New study reveals 33% gap in transplant access for UK’s poorest children

Dysregulated epigenetic memory in early embryos offers new clues to the inheritance of polycystic ovary syndrome (PCOS)

IVF and IUI pregnancy rates remain stable across Europe, despite an increasing uptake of single embryo transfer

It takes a village: Chimpanzee babies do better when their moms have social connections

From lab to market: how renewable polymers could transform medicine

Striking increase in obesity observed among youth between 2011 and 2023

[Press-News.org] Male birth defect is weakly linked to pesticide exposure, Stanford-led study finds