A clean environment is vital to human survival. The Earth’s resources are used in most aspects of everyday life. In using these, chemicals and toxins are released into the atmosphere which can affect human health. In a three part environmental health series at Lewis University, the health issues of asthma, mercury and lead were explored in depth.
Asthma
Asthma is an inflammatory disorder of the airways, making it difficult for people to breathe. Wheezing, coughing and shortness of breath are common symptoms, which worsen with activity and exercise. Emergency symptoms of asthma include: Tachycardia, which is a heartbeat over 100, chest pain, decreased alertness and cyanosis, or the bluing of lips, toes and nail beds.
Asthma affects 7 percent of the U.S. population and causes 4000 deaths a year. About 300 million people worldwide are afflicted with the disorder.
Triggers of asthma can be animals, dust mites, smoke, pollen, exercise and chemicals in the air or food. Other risk factors are a family history of the disease, athletics, socioeconomic factors, occupation and the hygiene hypothesis. The hygiene hypothesis is that people are too clean and are not able to build up much of immunity to common viruses and chemicals.
Asthma can’t be cured, but there are things that can help prevent attacks such as inhalers and corticosteroids. However, as long as there is particulate matter such as dust, smoke, sand, pollen and mist, there will be an increased frequency of asthma attacks requiring health care services.
Mercury
Mercury poisoning is an uncommon occurrence. Mercury was once used in teething powder. It was also a preservative in vaccinations, which was once thought to lead to autism. Humans can absorb all forms of mercury, but inhaling mercury is the biggest danger. This is because if one inhales it, it can stick to the lining of lung tissue and can cause lung inflammation, scarring the lungs.
Mercury poisoning can be diagnosed through blood and hair samples, but an individual would have had to accumulate a lot of mercury for it to cause serious health consequences.
“Mercury can get through the blood-brain barrier, which keeps out bacteria, but if mercury gets in, the barrier also blocks antibiotics,” Dr. Jerry Kavouras, assistant professor of biology points out. Symptoms include: trembling, vision problems and multiple personality disorders; it just depends on what part of the brain the mercury enters. Pinks Disease, the blocking up of blood vessels, is common in an individual poisoned with mercury.
How are we exposed to mercury? Volcanoes and geologic deposits are natural sources. Incineration of coal and metal mining releases mercury into the air, where it can circulate for years and have global distribution. Mercury is used in fluorescent lightbulbs, lightswitches, thermostats, medical devices, pain, pesticides and fertilizers. Fish also have mercury concentrated in their muscle tissue. Younger fish tend to have lower concentrations than older fish within the same body of water.
“Mercury is a persistent pollutant that doesn’t break down,” said Dr. Kavouras.
The threat lessens over time because it settles to the bottom of the lake beds and is covered by soil. Bioremediation, or mercury-resistant bacteria, is being introduced to absorb the mercury deposits
Plants are also now being genetically engineered to be mercury resistant and will degrade organic or inorganic mercury in its elemental form.
Lead
Lead poisoning has been known as plumbism and the signs differ when comparing affected adults to affected children. There is no known safe exposure level, and the effects can be devastating. The lead can enter the body through ingestion and inhalation in its inorganic form, and through the skin in its organic form. It can be stored in the blood for weeks, soft tissues for months, and bones for years. The lead leaves the body very slowly through the hair, nails and sweat.
Lead interferes with enzymes that make heme. It also affects any system that needs oxygen rich blood, which then decreases the blood quality. It interferes with neurotransmitter release in neurons, which is important in learning and memory.
“Treatment normally involves Chelation Therapy and endoscopy,” said Dr. Rago, assistant professor of biology.
Outcomes depend on the duration and extent of exposure. Effects on the blood, kidneys and other organs are usually reversible because it’s constantly regenerate. Nervous system damage is usually irreversible because that system doesn’t regenerate, making prevention key in avoiding lead poisoning.
Humans are exposed to lead through air, water, food, soil, paint and dust. Lead used to be used in gasoline and is still use in airplane fuel, the burning of which releases it into the air. Lead paint should not be disturbed if it is good condition, and is found primarily lead paint is mostly only around houses built before 1960.
The EPA estimates that more than 40 million U.S. residents use water that contains lead in excess of 15 ppb, which is the action level. Tap water must stay under this level for 90percent of homes tested or the EPA must take action.
“There are also elevated elemental lead levels in wildlife at the top of the food chain,” Dr. Kavouras said.
The elevated levels can cause many species to become endangered and permanently alter them. Cleaning up of the lead involves soil removal in lead-rich areas. Phytoremediation is also being enacted, where genetic plants will absorb lead and will then be extracted into a controlled environment.
Although the three environmental health hazards are very different, they are all naturally and human generated. It may seem that these dangers are everywhere, but steps are being taken daily to reduce the effects on both the environment and humans. Take the recommended precautions, but do not be afraid of everything that moves. Some exposure is natural; it’s excessive exposure that’s the real killer.
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