Halides: Understanding the risks and sources of exposure

As the world becomes more industrialised, we are constantly exposed to various chemicals in our daily lives. One group of chemicals that have recently come under scrutiny are halides, which are compounds containing halogen elements such as bromide, fluoride, chloride and iodine.

Halide ions are a negatively charged, colourless halogen atoms, these are highly soluble in water therefore they are easily found in environmental water bases such as sea, lakes and river. Another unexpected source of halides entails industrial runoffs and running water bedrocks. Halides can be found in a wide range of sources, from everyday household products like cleaning agents and disinfectants to industrial processes like paper production and wastewater treatment. In addition, halides are naturally present in some foods and even in the air we breathe.

However, exposure to halides has been linked to a number of health risks, including developmental and reproductive problems, thyroid dysfunction and even cancer. Children and pregnant women are particularly vulnerable to the harmful effects of halides, as their bodies are still developing. It is important for individuals to be aware of the sources of halides in their environment and take steps to minimise their exposure. This can include choosing natural cleaning products, avoiding processed foods with added halides and investing in air and water filtration systems.

Bromides

Bromides are commonly located in flame retardants, seafood, hot tub sanitizers, pesticides, fertilizers and in certain prescription medications. When bromine is introduced in our body (in the eyes, nose, lungs and/or throat) it induces irritation. If ingested it may cause adverse effects in the kidneys, if in contact with eyes can induce lacrimation and when introduced to the lungs can induce upper respiratory symptoms for a three-day duration. Other symptoms may include diarrhea, abdominal pain, vomiting and nausea.

Animal experiments indicate that bromine is a low acute oral toxin. Through rat experiments, the WHO discovered that longterm exposure to bromine intake results to a 50% chloride replacement in the plasma, kidneys, liver and brain. Other effects include weight gain in males and decreased thymus and thyroid weight in females.

Bromide-containing substances have a high correlation with cancer. The National Institute for Occupational Safety and Health (2010) classified one particular compound being methyl bromide, as a potential occupational carcinogen.

Fluorides

Fluorides have the ability to adhere to iodine receptors; therefore hindering thyroid gland function. Fluoride poisoning may induce an effect of hypothyroidism. Daily goods contain traces of fluorides, however its main source is water and non-dairy; US adults are noted for a fluoride intake of 66-80% in public drinking water. Other universal sources of highly fluoride concentrated sources include toothpaste (worst in children since they may swallow toothpaste), high intake of tea and inhaled fluoride (especially in China where coal is burned indoors). Fluoride absorption is commonly observed in the stomach and small intestine.

No evidence is recorded regarding adverse effects related with the ingestion of water with fluoride from the ranges of 0.5-1.0mg/litre. Having said so, India and China illustrated an increased risk of bone fractures at fluoride intake of 6mg/daily together with skeletal fluorosis with chronic fluoride intake, calculated to 14mg/day.

Excessive amount of ingested fluoride may induce bone disease, namely skeletal fluorosis, which may cause damage to bone and joints. This is caused since fluoride ingested undergoes chemical competition with calcium, therefore decreasing the calcium nutrition available for the proper and healthy development of bones and teeth. The World Health Organisation estimated a total of 2.7 million people being affected with this disease, commonly in India and China.

Chlorides

Chlorides can be found in natural salts, including sodium (sodium chloride), potassium (potassium chloride) and calcium (calcium chloride). The range of 200-300mg/L is the taste threshold commonly allocated for sodium chloride and calcium chloride in drinking water. Chloride may be found in diets such as seaweed, rye, tomatoes, lettuce, olives and

celery; in fertilizers as well as man-made soda. High concentration of chloride in the blood (also known as hyperchloraemia) may be caused by severe dehydration, diarrhea or metabolic problems such as kidney disease.

Food contains chloride at natural levels, ranging less than 0.36 mg/g, salt free diet documented average intake is that of 100mg/daily, however the additional salt during handling, cooking or eating is able to increase chloride intake ranging between 6g-12g/daily.

Sodium chloride intake exceeding 2.5g/daily has been reported to induce hypertension. There can also be the involvement of impaired sodium chloride metabolism, which may induce congestive heart failure.

Iodine

Iodine is a natural component of food; this may also be available in dietary supplements. Its main role, if ingested in adequate concentrations, is to regulate the thyroid hormones (commonly known as hormones thyroxine (T4) and triiodothyronine (T3), these are important in protein synthesis, aids in metabolic and enzymatic activity). Permissible levels of iodine for a 19-year-old adult is established to be not more than 1.1mg/L, since iodine toxicity would induce several diseases, such as hypothyroidism, hyperthyroidism and goiter. These symptoms may escalate to fever, abdominal pain, vomiting, diarrhea, weak pulse and coma.

Major iodine intake is through seaweed, cod, milk, shrimp, fish sticks, eggs, turkey breast, tuna, ionized salt and baked potato with peel.

Harmful substance regulations and safe discarding is very important to decrease the amount of harm these materials may inflict to the general population. Some guidelines which would result in the improvement of economical health includes the purification, testing and filtration of drinking water so as to remove high concentrations of water soluble chemicals, desalination of fluorides in drinking water and decrease the consumption of fertilizers. Other simple precautions to diminish the extent of these harmful substances may be taken through the washing of fruit and vegetables before ingestion, not using plastic bottles for an extensive amount of time and recycle.

Renald Blundell is a biochemist and biotechnologist with a special interest in Natural and Alternative Medicine. He is a professor at the Faculty of Medicine and Surgery, University of Malta

Eleanore Cricchiola worked as a staff nurse in 2013; graduated in Bachelors of Science (Honours) Health Science in 2016 and proceeded to graduate as a Doctor of Medicine and Surgery in 2021

Photo: AI-generated images created by Prof. Blundell