One of the heavily discussed water and food impurities in the last decade is aluminum. Today we will look at where it comes from in our drinking water, what the consequences are, and how to deal with it.
Sources of aluminum in water
There are several ways aluminum salts can enter water. First and foremost, these are:
- reagents for water treatment at water treatment plants;
- effluents from industrial enterprises, as well as atmospheric precipitation containing their emissions;
- Natural aluminosilicate minerals and clays that have limited solubility.
Aluminium – The Material That Changed The World
Natural aluminum intake into water
This element is the third most common in the Earth’s crust. Accordingly, it can come from natural minerals: clays and aluminosilicates. It is present in surface water, ground water, and even underground water. Human activity intensifies dissolution of natural minerals.
Data from the World Health Organization in 1997 indicate that aluminum concentrations in surface waters are typically less than 0.05 mg/l for neutral and alkaline waters, but may be higher for acidic waters (up to 90 mg/l). According to US studies conducted as early as the 21st century, aluminum content in groundwater may vary from 14 to 290 mg/l, and aluminum content in surface water may vary from 16 to 1170 mg/l. There is no systematic review of information regarding aluminum in Ukrainian natural waters. According to the ecological passports of the regions, its content in natural waters is elevated in:
- Zaporizhzhya region in some samples of Dnieper water already after its release from the aluminum plant;
- Luhansk region, rich in industrial enterprises saturated water of Seversky Donets river with aluminum.
These facts support the thesis that industry has the worst effect on water pollution.
Where does aluminum in drinking water come from?
Aluminum content in drinking water, is determined by its initial indicators, as well as how many impurities are added to it in the process of water treatment. When it comes to the reagents used in water treatment plants, there are two likely sources of contamination:
Aluminum sulfate and other salts used as coagulants to clarify water;
One of the most widely used coagulants is precisely aluminum salts, they help clean water from suspended particles, which include humic and fulvic acids, bacteria, etc. Aluminum in Ukrainian tap water can be found where the source of water intake is surface water bodies (rivers and reservoirs), but we do not use coagulants for purification of groundwater. We wrote earlier about how water coagulation works, and why aluminum sulfate is used in particular.
The maximum allowable concentration of aluminum in drinking water is 0.2 mg/l, similar recommendations give the WHO, the European directive on water quality and the legislation of most countries. In the U.S. the limit is set at 0.05 mg/l. Later we will explain why, but if you are interested in this topic, you can probably already guess.
What is the situation with drinking water in Ukraine?
With regard to the city of Kiev, where aluminum sulfate is used in water treatment, the situation is as follows: not less than 16% of samples exceeds the maximum allowable values, and only 10% of water samples, it was not detected at all, the remaining values are within 0.2 mg/l. In other areas, the situation is often similar.
In connection with low relevance of the topic there is no systematic research of water quality in Ukraine in respect of aluminum content, because there are more priority tasks.
Aluminum and Alzheimer’s: is there a connection?
Absorption of aluminum by human body is very low and does not exceed 1%. It depends on many factors: the presence of other compounds such as silica, pH, concentrations in water or food, etc. The primary route of excretion of aluminum is through the urinary system.
Doses of aluminum that are lethal to humans are unknown, because they are very high. Studies on mice and rats have shown that the lethal dose ranges from 200 to 1,000 mg per kilogram of weight.
As for toxic effects, doses over 100 mg/l can cause poisoning in animals. In the history of aluminum coagulants, there has only been one reported case of mass poisoning in the town of Kemelford in Britain. At the time, reported signs of poisoning in humans included nausea, vomiting, diarrhea, rashes, and joint pain.
As for nervous system disorders and Alzheimer’s disease proper, the situation is controversial, and research is continuing. Aluminum has been identified in amyloid plaques, which are one of the diagnostic signs of Alzheimer’s disease. This was followed by numerous studies, which were reviewed in detail by all of the organizations responsible for public health. The focus was on drinking water, although it is far from being the main source of aluminum intake into the human body, only 4% of daily intake is contributed by water, the rest a person gets mainly from food.
There is no definitive answer to the question of how aluminum is linked to the development of Alzheimer’s disease, but research confirms the link.
How to remove aluminum from water at home?
Removing aluminum from water at home can be done with a household reverse osmosis filter. In addition, it will help to remove other hazardous contaminants, including carcinogenic organochlorine, microbiological contaminants, and other heavy metals.
In fact, the relevance of aluminum to the rest of the problems of tap water is incredibly low. In general, even though there is no aluminum in it, it is better not to drink it raw. To learn more about the characteristics of water in different regions of Ukraine, please visit the relevant section of our blog.