Hazardous Pollutants: A Link To Spina Bifida?

Spina bifida is a birth defect that affects the spine and is usually apparent at birth. It occurs when the neural tube does not form properly or close all the way, resulting in damage to the spinal cord and nerves. The severity of spina bifida ranges from mild to severe, with some cases showing no symptoms at all. While the exact cause of spina bifida is not yet clear, a combination of genetics and environmental factors is thought to be responsible. Research has indicated that maternal exposure to certain hazardous pollutants, such as benzene, may increase the risk of spina bifida in offspring. Further studies are needed to fully understand the role of hazardous pollutants in the development of spina bifida.

Maternal exposure to benzene and other pollutants

Benzene is a known hazardous air pollutant, and there is evidence that maternal exposure to benzene is associated with spina bifida in offspring. However, there have been no assessments to evaluate the role of multiple hazardous air pollutants (HAPs) simultaneously on the risk of this relatively common birth defect.

The U.S. Clean Air Act of 1990 classified 188 environmental toxicants as HAPs, and the United States Environmental Protection Agency (U.S. EPA) identified 33 HAPs that present the greatest threat to public health. HAPs are a particularly important group of environmental toxicants because:

• They are known or suspected to cause a range of adverse health outcomes.
• Their levels are increasing in communities throughout the U.S.
• There are currently no national air quality standards for HAPs.

In a study, the association between maternal exposure to HAPs and spina bifida in offspring was evaluated using hierarchical Bayesian modeling that includes Stochastic Search Variable Selection (SSVS). The study found that two HAPs, quinoline and trichloroethylene, may be significant contributors to the risk of spina bifida.

Maternal exposure to benzene has also been linked to decreased birth weight, decreased head circumference during the second and third trimesters of pregnancy, and at birth, and decreased biparietal diameter during pregnancy.

Neural tube defects (NTDs)

Spina bifida is a type of NTD and is usually apparent at birth. It occurs in about 1 in every 2,875 births in the United States each year. The most common types of spina bifida include spina bifida occulta, meningocele, and myelomeningocele. Myelomeningocele is the most severe form, affecting around 1 in 1,000 live births and often resulting in paralysis or weakness in the lower limbs, as well as problems with bladder and bowel function.

The exact cause of NTDs is not clear, but a combination of genetics and environmental factors is thought to be responsible. Research has indicated that maternal exposure to certain hazardous air pollutants (HAPs), such as benzene, may increase the risk of spina bifida in offspring. Additionally, factors such as insufficient folic acid intake, uncontrolled diabetes, and overheating or fever during pregnancy may also contribute to the development of NTDs.

NTDs can be diagnosed during pregnancy or after birth through various tests, including blood tests, ultrasounds, and amniocentesis. While there is no cure for NTDs, treatment options such as surgery, physiotherapy, and medication can help manage the effects and prevent complications. Early diagnosis and intervention are crucial for improving long-term outcomes and reducing disabilities associated with NTDs.

The role of genetics and the environment

Maternal exposure to certain hazardous pollutants, such as benzene, quinoline, and trichloroethylene, is associated with spina bifida in offspring. However, the mechanism by which hazardous pollutants may lead to spina bifida is unknown. Potential mechanisms include genetic toxicity and oxidative stress, which may interact to contribute to teratogenesis.

Additionally, certain factors may increase the chance of having a baby with spina bifida, including:

• Not getting enough folic acid daily
• Diabetes that is not well-controlled
• Overheating or fever

Preventative measures

Spina bifida is a condition that affects the spine and is usually apparent at birth. It is caused by the incomplete development of the foetus' spine during the first month of pregnancy. The condition varies in degree, from mild with no symptoms to severe nerve damage.

• Folic acid: Folic acid, a water-soluble B vitamin often found in leafy green vegetables, plays an important role in the prevention of spina bifida. Women of childbearing age should take a vitamin with 400 mcg (0.4 mg) of folic acid every day. Studies suggest that taking this dosage of folic acid could reduce the incidence of spina bifida by up to 75%.
• Fever treatment: Treating any fevers immediately is important, and medications such as acetaminophen (Tylenol) can be used.
• Avoid overheating: Avoid hot tubs, saunas, or other activities that may cause overheating of the body.
• Manage diabetes and obesity: For those with diabetes or obesity, managing these conditions during pregnancy is crucial.
• Medication and supplement awareness: Inform your healthcare provider about any prescription medications, over-the-counter drugs, herbal supplements, and vitamins you are taking.
• Environmental factors: While the exact cause of spina bifida is not clear, a combination of genetics and environmental factors is believed to be the main cause. Reducing exposure to hazardous pollutants, such as benzene, may also help reduce the risk.

By taking these preventative measures, the risk of spina bifida can be minimised, and in some cases, the incidence of this condition may be reduced significantly.

Treatments and long-term effects

Spina bifida is a condition affecting the spine, usually apparent at birth, and caused by the neural tube not forming properly or closing all the way. The severity of spina bifida ranges from mild to severe. While there is no cure for spina bifida, there are treatments available to help manage the condition.

Surgery

In some cases, surgery can be performed to close the opening in the back, either during pregnancy or after the baby is born. This can help to reduce long-term disabilities associated with spina bifida, such as improving motor function and reducing the need for shunting. However, surgery also carries risks, including problems with the placenta and infection.

Physiotherapy and medication

Physiotherapy and medication can be used to treat some of the effects of spina bifida, such as muscle weakness and bladder and bowel function issues. These treatments may be needed throughout a patient's life to prevent and manage certain complications.

Catheterization

Children with more severe cases of spina bifida may require catheterization to pass urine.

Assistive devices

Children with spina bifida may require assistive devices such as braces, crutches, and wheelchairs throughout their lives.

Shunts

Infants born with myelomeningocele, the most severe form of spina bifida, often experience hydrocephalus, a buildup of spinal fluid on the brain. Plastic shunts must be surgically inserted beneath the skin to drain off the excess fluid and prevent brain damage, seizures, or blindness.

Learning support

Children with spina bifida, especially those who experienced hydrocephalus, sometimes have learning problems, including difficulties with language, math, and reading comprehension.

The long-term effects of spina bifida can vary depending on the severity of the condition. Some people with mild cases of spina bifida may not feel any effects at all, while others with more severe cases may have limited movement and learning development. Adults with spina bifida may experience additional complications, such as spinal cord tethering, changes in bowel patterns, orthopedic issues, loss of skin sensation, and sleep apnea.

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