Water contamination in Bahia: Is it safe to drink the tap water ?

If you are a traveler and you are visiting Brazil, you may wonder how the water quality is in the country.  Is it safe to drink water straight from the tap ? Do you have to buy mineral water in bottles ? Do you have to use filters? Are the local populations able to afford this? 

Water contamination in Bahia

Pesticides have been used for many years in agriculture and plenty of other fields. They are the main cause of contamination of water. Most of these pesticides are soluble in water and are transported from the agricultural soils to the groundwater and surface water by excessive rainfall and irrigation. This infiltration will naturally affect the quality of water and will resort to supplementary treatments that are  expensive.

Recent analysis carried out by Brazilian companies showed that high levels of 27 pesticides. have been detected in drinking water in 271 cities in Bahia, including Itacaré. 11 of these pesticides are even banned from use in Brazil. Not only agricultural areas are affected, urban and peri-urban areas also are.

Even though Brazil has a restriction of all these agrochemicals, their concentration exceeded the permitted level. This can be very harmful for human health. In the short term, they can lead to an acute intoxication, whose symptoms are headache, irritation of the skin or eyes, nausea, dizziness and fatigue, and in extreme cases to coma, cardiac arrest or loss of vision. They may weaken the immune system, affect the hormone system and cause infertility, neurological problems and many other dysfunctions in the long term. In addition, some of them are potentially cancerogenic. 

These pesticides may come from the potato, strawberry and tomato plantations in the farms in Bahia. This poses a real public health problem that should be taken seriously.


Then ... is it safe to drink the tap water in Bahia ?

Actually, the effects of pesticides on health depend on a lot of factors. They depend on the type of pesticide, on its activity and its mixture with other chemicals. They depend on the quantity of products ingested and the time of exposure to them too. Therefore, it is not easy to predict the exact effects of these pesticides on health and the risk of developing any of these diseases. It also means that they can act silently and cause a lot of damage without knowing the origin of the problem because we are exposed to a lot of other chemical products.

For all these reasons, the use of pesticides should be regulated, reduced and controlled constantly. For that we have to accept to change our habits and consume less.

Now we’ve seen that water in Bahia has been contaminated by pesticides and their adverse effects on health. Do we have to worry ? Not surprisingly, when there is a contamination like this one, it is preferable to avoid drinking tap water. Otherwise, it is generally safe to drink tap water in major big cities in Bahia and in hostels according to the Brazilian health ministry. They use filtration systems.  In remote areas, you have to pay more attention and prefer bottled water instead in case of doubt. Yet you can use it to wash your body, brush your teeth or rinse your food without worries. 



So how can we remove pesticides from tap water in houses? 

Reverse osmosis filtration and granulated activated carbon are the most effective systems to remove pesticides from drinking water. 

Reverse osmosis filters remove the impurities by driving the water through a semi-permeable membrane with pressure induced by electricity. This semi-permeable membrane is permeable to water and not permeable to other molecules. In other words, it allows water molecules to pass from the less concentrated to more concentrated solution and blocks ions and other molecules. Without the pressure, the water moves from the most concentrated solution to the least concentrated one so that the concentrations are equivalents in the two compartments. 


It is important to note that it removes essential minerals such as calcium and magnesium. The water must be mineralized after filtration.

Granulated activated carbon filters remove pesticides and other contaminants, but they require careful maintenance. In fact, they become completely useless if they are not replaced and regenerated regularly. In case of negligence, they can reject all the contaminants in the water.


It is possible to buy bottled mineral water, but the plastic bottles constitute both an environment and a health issue.

What about the local population ?

Despite all the efforts made in past years, access to quality water remains problematic in Brazil. There are still inequalities in access to safe water. There are five million people who do not have access to clean water and 25 million who need to improve their sanitation according to WHO/UNICEF. This represents a minority regarding the total population, but this doesn’t mean that they have to be neglected. Water pollution is also common in some regions, especially in the southeast. 

Although the disparities, tap water is yet globally drinkable in main cities in Brazil. However, many Brazilians don’t drink tap water and prefer drinking purified and bottled water. In fact, the water does not taste good because of the chlorine used to kill bacteria. Most of them use filters in their houses to improve water quality. They use coolers or faucet filters. Though, not all Brazilians are able to afford bottled mineral water or water filters. In rural areas, people drink tap water even if it contains contaminants. 

ETIV do BrasilComment