Definition: It is an alloy of mercury with another metal (silver, tin or copper) that is solid or liquid at room temperature.

Sources: The main source is when a person gets dental amalgam fillings in the teeth.

Uses: This is commonly used by dentists in filling holes or cavities in teeth. It is strong, durable and long lasting so less likely to break. It is a relatively cheap tooth filling.

Routes of exposure and health problems: Amalgam releases low levels of mercury in the form of vapor that can be inhaled and absorbed by the lungs. This will cause bronchitis and pneumonia. The mercury breathed in as vapors, enters the lungs and is distributed to the entire body, reaching all organs usually the kidneys.

Dental workers are more exposed to the vapors when placing or removing fillings, as well as the exhaust air from dental vacuum systems. Due to the long-term and regular exposure, the Central Nervous System is particularly affected. The neurological symptoms include increased excitability and tremors in fingers, eyelids and lips, which may progress to long term shaking of hands and feet. The amalgam in the teeth can also cause inflammation of the gums and production of excessive amounts of saliva with a strong metallic taste.

Aside from the mercury contained in amalgam, there is also either silver, copper or tin that can be harmful. Some of which include skin irritation, nausea, vomiting and diarrhea. The skin irritation in the form of rashes on the face or other parts of the body is an allergic reaction to the metals present in amalgam. However, these reactions are rare and removal of the filling usually resolves the problem.

Prevention: Nowadays, exposure of dental workers to dental amalgam are lesser compared to in the past because of improvements in technique and in hygiene measures, as well as because of the gradual decline in the use of amalgams.

For the consumer, it is best to avoid having tooth fillings using amalgam and use an alternative instead. Alternatives to amalgam include composite resin, glass ionomer, porcelain, and gold, among other options. Most consumers choose direct composite fillings because the white coloring matches the tooth better and the cost is considered moderate. Speak to your dentist about using a material that does not contain certain ingredients like that in amalgam.

Description: It is a soft bluish-white metal, which is malleable or flexible that can be easily cut with a knife. Cadmium is a very good electrical conductor.

Sources: It is found in certain plants such as tobacco, rice, potatoes, other cereal grains and other vegetables because these take cadmium from the soil. Meat can also be a source of cadmium especially sweet meats like liver and kidney. There are elevated amounts of cadmium in shellfish and mushrooms. It is released into the environment through unnatural ways such as mining and smelting. Groundwater seldom can contain cadmium, unless it is contaminated by industrial wastewater or seepage from hazardous waste sites. Levels are also increased in stagnant water found in household pipes.

Uses: It is used mainly in metal plating, in producing pigments, in rechargeable Nickel-Cadmium batteries, used as stabilizers in plastics and as a neutron absorbent in nuclear reactors. Cadmium compounds are used in black-and-white television phosphors and in blue and green phosphors for color TV tubes.

Routes of exposure and health problems: Cadmium has toxic effects on the body. It is mainly acquired through inhalation or ingestion. Most studies conducted suggest that health problems are associated with chronic occupational exposure to cadmium fumes and dusts. It can cause development of chronic obstructive pulmonary disease (COPD), chronic rhinitis, destruction of the olfactory epithelium leading to anosmia, and bronchitis. It can also be a possible cause of lung cancer.

Research by the National Institutes of Health, Department of Health and Human Services in the United States confirms that cadmium is linked to pancreatic cancer. Recent studies show that the main target organ by chronic cadmium exposure is the kidneys, whether through inhalation or ingestion. It would take approximately 10 years before onset of renal damage. It is associated with progressive renal tubular dysfunction that becomes irreversible. Early signs of real damage show elevated levels of creatinine and microscopic proteinuria. Kidney stones can also occur in cadmium-exposed populations due to hypercalciuria and hyperphophaturia.

Prevention: Because of prevalence of cadmium in the industry and environment, one must find ways to eliminate or at least, minimize exposure. Eat a healthy diet of organically grown, fruits, vegetables and meat. Stop smoking to prevent its entry into the lungs. Those working in industries exposed to cadmium, good occupational hygiene must be practiced. One should wear proper personal protective equipment such as respiratory protection, eye goggles, gloves, and protective clothing. Hands should be washed well before eating or drinking after work or during breaks. Showering and changing clothes immediately after working, and dispose the contaminated clothing on the work site. A clean working area should be maintained. The workplace must improve ventilation by opening windows; install an exhaust fan or mechanical ventilation system.

Definition: It is a shiny, silvery-white, odorless poisonous heavy metallic element that is liquid at ordinary temperatures.

Sources: Natural sources of mercury include volcanoes, forest fires, ore, and fossil fuels such as, coal and petroleum. There is now an increase in levels of mercury in the environment due to discharge from hydroelectric, mining, pulp, and paper industries.

Uses: The main use of mercury is in batteries, switches, lamps, and other electrical equipment, and it is also used in thermometers and barometers. Due to its high health risks, the uses of mercury has been phased out or at least been reduced.

Routes of exposure and health problems: This liquid form of mercury is especially dangerous because it vaporizes at room temperature. Inhalation is the main route of exposure to elemental mercury vapors and aerosols. If mercury vapor is inhaled, it is easily absorbed by the body, where it first gets into the lungs and from there into the blood and the brain. Respiratory symptoms include corrosive bronchitis or chemical pneumonitis with fever, chills, dry cough, chest pain and dyspnea, and this can lead to pulmonary edema or fibrosis, then to respiratory failure and death. The nerve poison, upon reaching the brain can cause sleep disorders, agitation, and paralysis. Acute high-dose inhalation of the vapor can be associated with proteinuria, nephritic syndrome, acute tubular necrosis and oliguric renal failure. It can also cause tachycardia and hypertension.

Elemental mercury that has been ingested into the gastrointestinal tract is not usually absorbed and so is unlikely to cause any acute toxicity from this route of exposure. However, it may induce vomiting and also result to gastrointestinal signs and symptoms such as metallic taste, salivation, nausea, dysphagia, abdominal cramps and diarrhea. Dermal reactions associated with dermal contact are rare. If it happens, the elemental mercury or vapor is also very slowly absorbed in high concentrations through the skin, thus causing irritation to both eyes and skin resulting in Contact Dermatitis. Acrodynia or Pink disease is linked with hypersensitivity to mercury and will develop to abnormal redness of the skin, followed by peeling of the skin on hands, nose and soles of feet. Because of mercury pollution which is found in air, land and water, this element can also be taken in our bodies through food.

Prevention: Rescuers in Hot zone areas exposed to mercury, wear a Positive-pressure, self-contained breathing apparatus (SCBA). Chemical protective clothing is recommended for skin protection. Gloves and foot protection are also advised because mercury spreads under the nails and other areas very easily.

Definition: Medicinal drugs that are made by pharmaceutical companies for remedy of symptoms, to diagnose, cure or prevent disease. In simple terms, it is called a “medicinal product”, referring to any substance or combination of substances that can prevent or treat disease.

Sources: Plants are the most important source of drug development. Different kinds of plants have been used to manufacture pharmaceutical drugs. Although there are some new approaches to drug discovery, such as combinatorial chemistry and computer-based molecular modeling design, none of the synthetic products can replace the role of plants since most of the core structures for these are based upon natural products. One example would be the first commercial pure natural product introduced for therapeutic use, is Morphine. This was during 1826 and comes from the Papaver somniferum, commonly known as the opium poppy. Another example would be the first semi-synthetic pure drug, Aspirin. This is based on the natural product salicin isolated from Salix alba, also known as the white willow, and introduced in 1899.

Uses: As a lot of people already know, pharmaceutical drugs are commonly used for our bodies to maintain good health. There are different types and so are classified in different ways based on their level of control, mode of action, route of administration, organ system affected or therapeutic effects. A sampling of classes includes: antipyretics for fever, analgesics to reduce pain, antibiotics to kill bacteria or inhibit their growth, antihypertensives to control blood pressure and many more.

Route of exposure and health effects: Pharmaceuticals or medicines can be administered in various ways. It can be given through inhalation, enteral (by mouth), rectal, topical (by skin), parenteral (in the blood), subcutaneous, or intramuscular. Aside from the health benefits that a drug provides, it can also affect one’s health in a manner that is not good. These are due to drug interactions, food interactions, overdosage or on a person’s health condition and body metabolism. Any adverse effect or condition might happen.

Prevention: Therefore, it is best to follow the recommended dosage and as much as possible, refrain from relying on drugs too often or immediately in the presence of a slight health problem. The usual organs that would be subject to danger is the liver, since it is in control for drug metabolism, and the kidneys that is responsible for elimination of drugs from the body.

Description: It is a stable, white crystalline, chlorinated hydrocarbon. It exists as a solid but is insoluble in water.

Sources: Hexachlorobenzene is detected in air at low levels, usually by incineration of chlorinated materials. It is also detected in ground water, drinking water and surface water. Due to which, it is accumulated by aquatic organisms like fish and shellfish. It is also found in soil near production and waste disposal sites.

Uses: It is mainly used as a fungicide which kills or inhibits the growth of fungi in swimming pools and other materials. It is also used in the manufacture of dyes, synthesis of organic chemicals, plastics, rubber and in wood preservation. It is also a pesticide, used for killing pests such as rodents or insects.

Routes of exposure and health problems: The primary route of exposure is from food especially intake of fatty fish. Although, all routes via ingestion, inhalation or dermal contact may cause toxicity. Children may be exposed by playing on contaminated soil. There will be irritation in the eyes, skin and mucous membranes. It can also cause seizures, pneumonitis and respiratory depression. Prolonged periods of ingestion may cause Cutaneous Porphyria, which is a liver disease associated with skin lesions. It is also a possible carcinogen that can lead to cancer in the liver, thyroid or kidneys due to oral exposure. Hexachlorobenzene can affect fertility and cause damage to the embryo or unborn child. It will be passed on via lactation and cause harm to breastfed children.

Prevention: In situation where overexposure is more likely to occur, for the eyes, a face shield or eye goggles is recommended. For the skin, wear protective gloves and clothing. In all cases overall, a self-contained breathing apparatus to prevent inhalation. If already exposed via inhalation, one should be moved immediately to a place with fresh air. After skin exposure including hair and nails, these should be washed vigorously with pure clean water. Eyes should be washed with running water for at least 15 minutes after exposure.

Description: It is a polycyclic aromatic hydrocarbon derived from anthracene. Physically, it appears as yellow crystals or powder. It is poorly soluble in water.

Sources: Anthraquinone is an organic compound that is found in some plants. These are aloe, Cascara sagrada, Frangula (buckthorn), Rhubarb, and Senna. Anthraquinone is also released to the environment from gasoline and diesel exhausts, from municipal waste incineration and burning of forest materials.

Uses: It is used in the manufacture of dyes, in the textile and paper pulping industries, and as a bird repellant for seeds. It also has the following qualities: antibacterial, antiviral, antifungal, emetic and insecticide. The most common medicinal use of anthraquinones is its laxative effects. It brings about relief of constipation by stimulating colon contractions and it increases the amount of fluid.

Routes of exposure and health problems: Exposure to this may cause skin and eye irritation, an allergic skin reaction having itching and a skin rash, and may also cause urine discoloration. It may be harmful by inhalation, ingestion or skin absorption. Severe poisoning may cause seizures and coma.

Prevention: As a preventive measure, use protective eye equipment such as safety goggles, even when wearing contact lenses. Use personal breathing protection like respirators, or a local exhaust for ventilation. Wear protective gloves. Do not eat, drink, or smoke inside work vicinity.

Description: It is a halogen element that appears as a heavy greenish yellow gas with a pungent odor. It is incombustible and water soluble.

Sources: Naturally, chlorine does not exist by itself in the environment, but only in combination with other elements. Chiefly, it is combined with sodium thus producing the common salt (NaCl). In some rare situations such as in human tears, free chlorine can be detected. Chlorine can be found in food, most commonly in the Cabbage family of vegetables that includes, cabbage, cauliflower, broccoli, and Brussel sprouts.

Uses: It is used especially as a bleaching, oxidizing agent, and a disinfectant in water purification, such as in drinking water and swimming pools, as it can kill bacteria, parasites and other harmful organisms. It is also used in the sanitation process for industrial waste and sewage. Most prescription and over-the-counter pharmaceuticals contain or are manufactured with chlorine. Some of them include pain relievers, decongestants, antihistamines and antibiotics.

Route of exposure and health problems: Exposure with too much chlorine causes breathing problems, such as coughing, chest tightness, shortness of breath, as this is suffocating. It will eventually lead to bronchial inflammation and respiratory damage when exposed at a high concentration in a short period of time or at a low concentration for a longer duration. It can affect all the sensory organs – sight, hearing and touch. This can result to blurred vision, watery eyes, burning sensation in the nose, throat and eyes, burning pain, redness, and blisters on the skin. Other symptoms of chlorine toxicity include palpitations, which indicates a probable heart disease; and nausea and vomiting, that occurs with excess hydrochloric acid.

Prevention: Since it is already known that chlorine is present in pools and in the sea, this is why it is recommended that one applies protective lotion which reduces exposure. Aside from which, one should wash their entire body and rinse hair thoroughly, before entering and after getting out of both the pool and the sea. Industries that are exposed to chlorine have portable gas detectors and fixed gas detection systems to help protect the workers, in cases of accidental leaks.

Description: It is a nonmetallic halogen element, highly volatile, that appears as a reddish brown liquid in room temperature, thus known as the only nonmetal to exist as liquid form at room temperature. It has a strong bleach-like odor and it dissolves in water.

Sources: In the environment, Bromium is found in the earth’s crust and it occurs in compounds present in seawater, natural brines and salt-lake evaporates. Just like chlorine, it can combine to sodium. This produces the compound, sodium bromide, but in lesser amounts compared to sodium chloride.

Uses: It has a lot of uses and is found in pesticides, agricultural chemicals, dyes, pharmaceuticals, sanitizers, furniture foam, gasoline, and film photography. Bromium is flame resistant, and due to this characteristic it is found in special plastics like those used as covers for appliances. It is also for water purification.

Routes of exposure and health problems: Bromium is hazardous and highly toxic. It is corrosive to human tissue. One may come in contact through ingestion of contaminated food or water causing nausea, vomiting and other gastrointestinal symptoms. Inhalation leads to coughing and breathing problems, while skin contact results to irritation burns and lesions. Other signs and symptoms of exposure are headache, dizziness and watery eyes. Bromium damages many major organs including the liver, kidneys, lungs and stomach. There are some cases, it can cause cancer. It may also have other health dangers including thyroid dysfunction. It competes with iodine in the formation of thyroid hormones leading to hypothyroidism, goiter and hormonal imbalance.

Prevention: For those subject to exposure, they are required to have safety goggles, face shield, protective gloves and protective clothing, in combination with breathing protection. Do not eat, drink or smoke within work vicinity.

Description: It is a hydrocarbon that appears as a colorless, flammable gas with a sweet and musky odor.

Sources: It is mainly found in plants as a natural plant hormone which regulates plant growth, thus is used in agriculture to force the ripening of fruits and vegetables. It is highly active at low concentrations. As the concentration increases, there will be an associated degree of damage to its surroundings. There are also nonliving sources of ethylene and these include, improperly adjusted or unclean greenhouse heating units, leaky gas lines, and exhausts from combustion engines.

Uses: In combination with other substances, it forms compounds that have different uses. When it undergoes polymerization to form polyethylene, it is a plastic material that is used in packaging films, wire coatings and squeeze bottles. When it is combined with sulfuric acid, it forms a mixture of sulfates that is hydrolyzed to ethylene alcohol, which is commonly used as a disinfectant. The reaction of ethylene and oxygen gives ethylene oxide that is used in the manufacture of antifreeze and detergents.

Routes of exposure and health problems: Primarily, exposure with ethylene is through inhalation, but can also enter the body by dermal contact. It is normally of low toxicity to humans and is unlikely to have any adverse effects. However, one should consider that extremely high levels still have the capacity to cause health problems such as headache, drowsiness, dizziness, nausea, weakness and unconsciousness.

Prevention: Use local exhaust ventilation at the site of exposure, or individual respirators. Wear protective clothing.

Description: It is a hydrocarbon that appears as a colorless, flammable gas with a sweet and musky odor.

Sources: It is mainly found in plants as a natural plant hormone which regulates plant growth, thus is used in agriculture to force the ripening of fruits and vegetables. It is highly active at low concentrations. As the concentration increases, there will be an associated degree of damage to its surroundings. There are also nonliving sources of ethylene and these include, improperly adjusted or unclean greenhouse heating units, leaky gas lines, and exhausts from combustion engines.

Uses: In combination with other substances, it forms compounds that have different uses. When it undergoes polymerization to form polyethylene, it is a plastic material that is used in packaging films, wire coatings and squeeze bottles. When it is combined with sulfuric acid, it forms a mixture of sulfates that is hydrolyzed to ethylene alcohol, which is commonly used as a disinfectant. The reaction of ethylene and oxygen gives ethylene oxide that is used in the manufacture of antifreeze and detergents.

Routes of exposure and health problems: Primarily, exposure with ethylene is through inhalation, but can also enter the body by dermal contact. It is normally of low toxicity to humans and is unlikely to have any adverse effects. However, one should consider that extremely high levels still have the capacity to cause health problems such as headache, drowsiness, dizziness, nausea, weakness and unconsciousness.

Prevention: Use local exhaust ventilation at the site of exposure, or individual respirators. Wear protective clothing.