The biological contaminants are those living beings or products derived from these that invade an environment producing unwanted effects by humans. Organisms that are part of all known taxonomic groups such as bacteria, archaea, protists, fungi, plants and animals can act as biological contaminants..
These pollutants affect the environment in general, causing problems for the soil, water, air, food, infrastructure and work spaces. Weeds, pathogenic fungi and nematodes are found in agricultural soils, while pathogenic bacteria and protists are a serious threat to public health in water..
Air is also a medium susceptible to biological contamination, as well as an efficient vehicle for transporting pollutants. Airborne viruses, bacteria, and fungal spores are transported long distances.
On the other hand, organisms such as bacteria, protozoa, fungi, insects, and mammalian excreta contaminate food and drinking water. Likewise, there are biological contaminants in work environments, educational centers, health centers and homes..
The presence of biological contaminants results in public health problems that imply economic losses in prevention and remediation. Food production is also affected by biological pollutants that affect crops or deteriorate already processed foods..
Article index
Biological pollutants are made up of living organisms and by products derived from their metabolism. Among living organisms, all biological kingdoms are represented and, in the case of metabolic derivatives, toxins and metabolic waste (feces and urine) stand out..
Although in a strict sense viruses do not fit the definition of life, they are normally considered in this area. Thus, viruses are high-impact biological pollutants due to their reproductive and invasive capacity..
Viral pandemics are becoming more frequent, such is the case of the recent crisis with pneumonia caused by the 2019-nCoV coronavirus. Depending on the type of virus, these can spread through the air, by contact or by vectors such as mosquitoes (mosquitoes).
Bacteria are another of the main biological pollutants that cause health problems in humans, animals and plants. They are spread through water, food, through the air, or by direct contact. They can contaminate all environments: soil, water, food and infrastructure and objects.
Protozoa can contaminate aquatic environments, the soil, and even be transported in atmospheric dust. Some form cysts that make them resistant to high temperatures, desiccation, and even disinfection..
Protozoa like Acanthamoeba cause encephalitis and corneal conditions, others such as Naegleria fowleri they cause serious diseases such as primary amoebic meningoencephalitis. Many other species are intestinal pathogens that contaminate through feces.
There are many species of pathogenic fungi that pollute the environment, affecting human, animal and plant health. Being spread by spores, they are efficiently dispersed through the air, and they also pollute soil and water.
Many plant species act as weeds, contaminating agricultural soils and affecting crop productivity. They are also a reservoir for other contaminating organisms such as viruses, fungi, bacteria and insects. Weeds affect crops in the soil and bodies of water, where they participate in the eutrophication process.
Various animal species are pests of crops and animals, as well as humans and can be vectors of diseases. Insects are the most problematic group in this regard, with blood-sucking species such as lice, ticks, fleas, and mosquitoes..
Likewise, rodents, especially domestic ones such as the common rat and mice, are important pests. In turn, the excreta and urine of these animals contaminate food and transmit diseases.
On many occasions, the agent of biological contamination is not directly the living organism, but products derived from its metabolism..
Species of bacteria, fungi, algae, plants and animals produce toxins as defense, which once in the environment become pollutants. They can be transferred along food webs, affecting biodiversity and humans..
An example is toxic algal blooms (red tides) which are population explosions of toxic phytoplankton algae due to ecological imbalances. The populations form patches covering extensive marine areas, intoxicating various aquatic organisms that affect them when consumed by humans..
The most common case in this line is the contamination of stored food by the feces and urine of rodents. For example, leptospirosis, a disease caused by the bacteria Leptospira interrogans, spread by coming into contact with the urine of rats or other animals.
Although rare, certain structural components of living things can also be pollutants. Such is the case of the prions that cause bovine spongiform encephalopathy or 'mad cow disease'.
It is a defective protein that conditions a degenerative picture of the central nervous system, causing death. It affects both animals and humans by being transmitted through the consumption of infected meat.
With the development of genetic engineering, particularly of genetically modified organisms, a new type of biological contaminant appears. These are genes that, in an unplanned way, are integrated into the genome of another organism different from its species, and can cause problems for humans..
Beyond human manipulation, nature takes its course and genes inserted into one species can be transferred to another unwanted one. For example, a herbicide resistance gene included in a cultivated species that is passed on to a weed-related species.
Another potential problem is the inclusion of a gene from one species that causes allergy to a segment of the population in another species. If the individual does not have adequate information, this can lead to serious health problems..
Biological pollutants can be classified by both the polluting organism and the polluting medium. In the latter case, these pollutants invade all the environments where the human being develops.
Soils are contaminated with fungi, bacteria, protozoa, weeds and animals such as nematodes among others. These organisms cause health problems in crops, animal production systems and human health.
Soil fungi, bacteria and nematodes cause agricultural losses by affecting the root systems of plants.
Contact with soil contaminated by protozoa and flatworms is one of the main sources of childhood intestinal diseases. This type of disease is the main cause of infant mortality in the world.
Water is a medium very susceptible to contamination, especially by biological pollutants that achieve an adequate vital environment and dispersal medium. Bacteria, protozoa and animals are found in water bodies as biological contaminants in different contexts.
Bacteria, protozoa and human pathogenic animals such as flatworms (tapeworms and others), reach the water mainly through contaminated excreta.
Water can be contaminated with biological toxins, for example those contained in toxic phytoplankton algae in toxic algal blooms. An example is the dinoflagellate Gymnodinium catenatum, which produces a paralyzing saxitoxin.
The excreta and feces of animals in the water are also carriers of pathogens such as the protozoan Toxoplasma gondii (toxoplasmosis). Schistosomiasis or bilharzia is a disease that is contracted in waters infected by human excreta and is caused by flatworms of the genus Schistosoma.
Air is a means of dispersal of biological pollutants, with viral particles, bacteria, fungal spores and pollen grains in suspension. The case of pollen grains and spores is particularly relevant as they cause allergies and respiratory diseases..
As living matter is the natural substrate for many living organisms, food is a material susceptible to biological contamination.
Bacteria and fungi are the main contaminants in food, many of them capable of causing disease in humans.
Most cases of food poisoning are caused by bacteria in food or water. Among the most common are those caused by Escherichia coli species Salmonella and by Staphylococcus.
In some cases, biological contaminants in food can secrete deadly toxins, such as bacteria. Clostridium botulinum. The bacteria that cause botulism can contaminate any food, being very resistant to high temperatures. It is capable of producing botulinum neurotoxin, considered the most powerful that exists.
Fungi by contaminating food can also secrete mycotoxins, such as aflatoxins that have carcinogenic and mutagenic effects. Food can also be contaminated by the excreta and urine of animal pests such as rodents..
When contaminating food stores in search of food, rodents disperse their feces and urine, contaminating food products. In particular, the urine of mice and rats carries Hantavirus, leptospirosis and Salmonella.
Biological contaminants, such as bacteria, fungi, insects, rodents, and others are a major problem in human environments. In addition to being transmitters of diseases, they deteriorate infrastructures, render useless spaces and hinder work activities.
In medical centers, contamination with bacteria and fungi represent a serious problem, especially in areas that require total asepsis, such as operating rooms. In health centers without adequate hygiene, cases of nosocomial pneumonia are common, which is pneumonia contracted in the health center itself.
It has been pointed out that about 40% of in-hospital health complications are related to biological contamination of the center. This is a major cause of death, especially when it comes to bacteria that are multi-resistant to antibiotics such as Pseudomonas aeruginosa 35.
The concept of sick building syndrome causes deteriorated infrastructures to present chronic problems of biological contamination. Among the most characteristic biological contaminants of this syndrome are viruses, fungi, bacteria and mites.
The main consequence and of greatest impact are the affections to human health caused by biological pollutants. Infectious diseases are one of the main diseases and are caused by biological agents that contaminate all types of environments and foods..
Biological contaminants in the form of pests and weeds affect the yield and productivity of crops and farm animals. Similarly, food reserves decrease when consumed in storage or contaminated.
Water is a vital element for life and the biological pollutants present in it make it dangerous for consumption. Currently humanity faces a deficit of drinking water, so that the contamination of the few available sources is a global problem.
Biological pollutants are involved in a large part of the environmental alterations that cause ecological imbalances. This in turn results in the loss of biodiversity, by decreasing populations and even extinction of species.
The contamination of areas with exotic species is an important cause of the disappearance of local species due to predation or advantageous competition. For its part, eutrophication is one of the main problems in aquatic ecosystems, caused by an excessive entry of nutrients into the environment..
The areas of housing, basic services and human work are deteriorated and even disabled by biological pollutants.
Yet No Comments