All You Need To Know About Biological Contamination And Its Sources

biological contamination

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Biological contamination – the very term alone can send shivers down one’s spine. The possibility of tiny, little monsters, hidden from the naked eye, crawling right on top of the piece of pizza you’re just about to pop into your mouth can be rather uncomfortable; uncomfortable but fascinating as well.

So, to pack all your misconceptions away, this blog is here to save the day!

From getting to know what are biological contaminants in detail to learning about their possible sources with examples, we will equip you with all the necessary knowledge to ensure that you’re good to go.

So buckle up as we dive into the world of biological contamination like never before!

What is biological Contamination?

So, what is biological contamination; the one everyone so often fears? In theory, it refers to the presence of harmful microorganisms or pathogens in food, water, and other ingestible substances. 

These pathogens include:

  • Bacteria
  • Viruses
  • Fungi

These little trouble-makers can cause a wide range of potential illnesses from ordinary stomach flu to fatal infections. They can come about in many ways including:

  • Contaminated soil
  • Improper handling of food
  • Poor hygiene practices.

Where these pathogens mostly dwell are areas such as

  • Unsanitary food preparation practices
  • Undercooked/raw meat
  • Contaminated water
  • Unwashed fruits and vegetables

Symptoms of illnesses caused by biological pollutants include:

  • Fever
  • Dehydration
  • Diarrhea 
  • Vomiting

In short, biological contamination is the bane of our existence; a serious health risk that can be avoided by following a few easy steps. Therefore, we must all follow all necessary measures to ensure our food is safe to eat and our water is healthy to drink.

What are the main types of biological contamination?

Types of bacterial contamination may be few but each one of them has its sources, effects, and resulting consequences. Most contaminations are transmitted through fecal routes and water systems.

Read on to find out what are biological contaminants, their types, and everything there is to know about them.

  • Bacteria: 

Bacterial contamination occurs when harmful bacteria contaminate food, water, or other substances. Such harmful bacterial contaminants include Salmonella, Listeria, and Escherichia coli (E. coli). 

These bacterial pathogens have the ability to potentially cause serious damage to human health resulting in various food-borne illnesses with symptoms including

  • Fever
  • Diarrhea
  • Vomiting

Food that has not been properly kept or stored falls prey to these tiny microorganisms, as can food that has been in any way in contact with contaminated surfaces or utensils. This type of contamination can also occur through contact with animals, such as farm animals or pets. 

In order to prevent or avoid such bacterial contamination, proper sanitary and hygienic practices, cooking food to the appropriate temperature, and avoiding cross-contamination between raw and cooked food.

  • Fungi (molds and yeasts):

Fungal contamination is a phenomenon that occurs when harmful fungi contaminate food or any contaminated surface. This type of contamination leads to foodborne illnesses such as fungal infections or respiratory problems. 

Some of the most common fungal contaminants include:

  • Aspergillus
  • Penicillium
  • Candida.

They mostly thrive in damp or moldy environments. They can also be found in the air and on surfaces such as countertops, floors, and walls.

In order to prevent fungal contamination, the following techniques can be practiced:

  • Maintaining a clean, dry, and healthy environment
  • Storing food at appropriate temperatures
  • Avoiding cross-contamination between cooked and undercooked food items.
  • Virus: 

Like bacteria, viral contaminations also occur when harmful viruses enter the human body through contaminated food, water, or any contaminated surface. 

Some of the most commonly found viral contaminants are:

  • Norovirus
  • Rotavirus
  • Hepatitis A

Illnesses caused by viruses show the following symptoms:

  • Fever
  • Vomiting
  • Diarrhea
  • Dehydration

Viruses are known to spread rapidly from one host to another, especially in crowded environments, where people are in close proximity to each other. Preventing viral infections involves

  • Washing hands frequently
  • Disinfecting frequently-touched surfaces
  • Avoiding contact with those who are sick 
  • Parasites 

Parasitic contamination also occurs through contaminated food, water, animals or contaminated surfaces. Some common parasitic contaminants include:

  • Giardia
  • Cryptosporidium
  • Toxoplasma

Symptoms of parasitic contamination include 

  • Diarrhea
  • Abdominal pain
  • Weight loss

Parasites are often found in soil, water, and undercooked meat. Preventing parasitic contamination involves 

  • Practicing good hygiene
  • Cooking meat to the appropriate temperature
  • Avoiding contact with animal feces
  • Toxins

In some cases, toxins are also considered a type of biological contaminant. They are typically released by harmful pathogens such as bacteria and molds that contaminate food which then adversely affects the health of its consumers. 

Such type of contamination is termed as food intoxication, since here, it is the toxin that causes the foodborne illness rather than the pathogen releasing it. Surprisingly, they are far more resistant to preventive techniques than the pathogens releasing them.

What are biological contamination examples?

‘There are at least 250 identified foodborne illnesses known to the food industry; the majority of these illnesses are attributed to biological contamination.’ – The Centers for Disease Control and Prevention


Here are a few biological contamination examples that have occurred in recent years:

1. E. Coli Outbreak

A horrible outbreak of E. coli contamination was reported in 2018 in the United States, affecting 36 states and resulting in 210 infections. The source of the contamination was traced back to romaine lettuce from Yuma, Arizona. The Centers for Disease Control and Prevention (CDC) linked the outbreak to a strain of E. coli found in irrigation canals used to water the lettuce.

2. Legionnaires’ Disease Outbreak

In 2019, an outbreak of Legionnaires’ disease was reported in Atlanta, Georgia, affecting at least 12 people and causing one death. The source of the contamination was traced back to the Sheraton Atlanta Hotel, where the bacteria had been found in the hotel’s cooling tower and plumbing systems. Legionella bacteria can cause severe respiratory illness in humans and can be fatal in some cases.

3. Salmonella Contamination

In 2020, a salmonella outbreak was reported in the United States, affecting 34 states and causing 212 infections. The source of the contamination was traced back to red onions from Bakersfield, California. The CDC advised consumers to avoid eating and dispose of any red onions that were purchased or received between May and July 2020.

4. Listeria Outbreak

A major outbreak of Listeria contamination in 2011 caused the death of 33 people in the United States. The source of the contamination was traced back to cantaloupes from Colorado, which were contaminated with Listeria bacteria during the washing and packing process. The outbreak resulted in a massive recall of cantaloupes across the country.

5. Cryptosporidium Outbreak

In 2016, a Cryptosporidium outbreak was reported in Milwaukee, Wisconsin, affecting over 400 individuals. The source of the contamination was traced back to a public water system that provided drinking water to the city. Cryptosporidium is a parasite that can cause severe gastrointestinal illness in humans and can be transmitted through contaminated water sources.

6. COVID-19 Pandemic

The COVID-19 pandemic is a current and ongoing example of biological contamination. The virus, which originated in Wuhan, China, quickly spread worldwide, causing a global health crisis. The virus is highly contagious and can be transmitted through respiratory droplets, making it difficult to control. The pandemic has led to widespread illness and death, as well as significant disruptions to daily life and the global economy.

What are the 4 sources of biological contamination?

Biological contamination is a serious issue that arises from the presence of harmful microorganisms in different environments such as food, water, and air. Biological contamination may result from different sources including human, animal, water, and air. In this article, we will discuss the 4 sources of biological contamination in detail.

  1. Human Source

Humans can be a source of biological contamination in various settings. We can carry and spread microorganisms such as bacteria, viruses, and fungi, which can cause disease or infection. Illnesses such as the flu, gastritis, and several others can easily spread through direct contact with infected humans, respiratory secretions, or saliva. Poor personal hygiene practices can encourage the growth and spread of microbes, such as washing hands inadequately after using the bathroom or coughing and sneezing into the hand instead of using a tissue.

Humans can also be a source of biological contamination in the agricultural sector. Farmers may harbor bacteria such as E. coli, Salmonella, or Listeria through exposure to fecal matter from animals or contaminated water sources. If these bacteria come into contact with food products, it can cause outbreaks of foodborne illness or disease.

  1. Animal Source

Animals can also be a source of biological contamination in different environments. Microorganisms like bacteria and viruses may live in animals’ digestive tracts, respiratory tracts, or on their skin, from where they can spread to food and other surfaces. For example, farmers can transmit pathogens from animals to humans through direct contacts, such as through scratches or bites, or by consuming animal products contaminated with harmful bacteria.

In addition to direct contact with animals, improper animal waste disposal can spread harmful microbes into the environment. 

  1. Water Source

While water may be the building block of life, it can work as a multiplying pool for harmful pathogens such as bacteria, viruses, and other microorganisms. Industrial wastewater can also contain high levels of hazardous chemicals. Humans can contract waterborne illnesses and diseases, and animals can also become ill due to exposure to contaminated water sources.

  1. Air Source

Air is another source of biological contamination that can harm human health. Airborne microorganisms like bacteria or viruses can thrive in different environments such as healthcare facilities or crowded areas like public transport systems. Infectious diseases such as tuberculosis or flu can be transmitted through inhalation of contaminated air. Airborne contaminants may also be environmental, for example, mold spores can trigger allergies or structural damage to buildings.

How to detect biological contamination?

Harmful pathogens are termed as such since they are not visible to the naked eye and have the tendency to contaminate even the healthiest food. However, technological advancements have made it easier to adopt a few practices and techniques that may help detect and avoid biological contamination.

The technique used solely depends on the intensity and duration of the contamination. But rather than the type, the effectiveness and efficiency of the type or technique is what matters the most to people in the food business. 

Let’s look into a few solutions for biological contamination management:


Once a pathogen contaminates certain food, the effect of its presence becomes apparent on its surface. To have a more accurate observation, medical specialists use the following methods,

  • Microbial Plating: In this method, the samples of the contaminated food are diluted and placed in a growing medium and then observed under a microscope to see if a pathogen is present. It is widely used to quantify the contaminants and analyze whether they possess any real threat. This technique often helps to double-check other advanced detection methods.
  • Advanced test kits: This method is comparatively faster than the microbial plating method. It can generate more accurate results as this method is rather specific and fast as well. This makes it more expensive than other methods of detection.

All-in-all, the detection of pathogens in contaminated food and water plays a very crucial role in the development of a proper food safety plan.  Hospital data mining can help correlate these detection methods with patient outcomes and epidemiological trends, informing more effective food safety strategies.

How to avoid biological contamination?

Preventing biological contamination is critical to avoid illnesses and disease outbreaks since they can occur at any time and anywhere. Here are some steps to prevent biological contamination:

1. Proper Handwashing

Handwashing is the most crucial step in preventing biological contaminants from spreading. Employees who handle food, work in healthcare or childcare settings, or handle hazardous materials should wash their hands frequently using soap and warm water for at least 20 seconds.

2. Sanitizing Surfaces

Proper sanitization of surfaces where food is prepared, consumed, or stored can reduce the risk of contamination. Surfaces should be sanitized at least daily, and more frequently if heavily used or potentially exposed to contaminants.

3. Safe Food Handling

Safe food handling practices can minimize the risk of foodborne illnesses. Employees who handle food should wear gloves and hairnets to minimize the transfer of pathogens. Food should be stored at the right temperature and cooked to the appropriate temperature to ensure that biological contaminants are destroyed.

4. Proper Waste Disposal

Waste disposal is essential in preventing biological contamination of food. Properly label and separate hazardous waste from regular waste, including medical materials, chemical waste, infectious substances, and sharps.

5. Water Treatment

The treatment of water that is consumed or comes into contact with food is critical to preventing biological contamination. Water should be treated using physical methods such as filtration, disinfection techniques such as chlorination, and ultraviolet light to remove or kill microorganisms.

6. Use of Personal Protective Equipment (PPE)

Personal protective equipment such as gloves, goggles, masks, and lab coats should be used when working with hazardous material and pathogens. PPE serves as a protective barrier between the employee and any potential contaminants.

7. Routine Inspections

Routine inspections can identify potential hazards and prevent contamination from occurring. Inspections can help to identify areas that require maintenance or repair and areas that require more frequent sanitization.

How EcoDocs – a Food Safety Management System Can Help?

Folio3’s Ecodocs, a leading food safety software, is the key to unlocking unlimited productivity and efficiency in the realm of food safety. It is a cloud-based CMMS software that promises state-of-the-art services, simplifying the maintenance of important data effortlessly.

Ecodocs is by far the easiest and fastest software to use, aiding maintenance managers worldwide in effectively managing their tasks. It operates in a paperless environment for document management and record-keeping, ensuring compliance with FDA’s food safety standards.

Traditional methods of documenting and storing information can potentially increase the risk of biological contamination, as physical documents can serve as a source of transmission, especially if they’re decades old. However, EcoDocs can significantly reduce the chances of such contamination by eliminating the need for physical documents altogether.

Another way EcoDocs, the food safety software, can help prevent biological contamination of food is by ensuring that all essential documents are stored in one central, designated location. This means that employees who need to access the information can do so quickly and easily without spending excess time searching for physical files. With EcoDocs, documents can be accessed in real-time, from anywhere and at any time, which is crucial in preventing potential hazards.

Ecodocs also ensures proper compliance with FDA’s regulatory standards, crucial for maintaining a safe and healthy workplace environment. By utilizing EcoDocs, organizations can store, manage, and retrieve essential documents required for maintaining regulatory compliance. This prevents the risk of biological and other forms of hazards that could lead to penalties, legal action, and damage to the organization’s reputation.

Furthermore, EcoDocs can provide proper documentation of hygiene and disinfection procedures used to prevent biological contamination. For example, a cleaning procedure can be documented on EcoDocs, and employees can sign off on each step, demonstrating that proper protocols were followed to prevent contamination risks.

Overall, EcoDocs, the food safety software, plays a pivotal role in significantly aiding in preventing biological contamination, ensuring a safe and healthy workplace in the food industry.

The Takeaway

All-in-all, no matter what the quantity or the quality of food may be while leaving the site, it is all equally in danger of biological contamination that may take place whenever and wherever it wishes. Hence, food businesses need to be very vigilant when it comes to preventing the attack of harmful pathogens and use the right methods to detect, analyze and eradicate their presence to ensure a healthier environment. These can effectively be done using digital technologies and software solutions. Folio3 is the best software provider in the food industry. The software solutions help keep track of every activity performed at the facility. 


Q1: What is a type of contaminant that can cause foodborne illness?

Below are a few contaminants that cause food-borne illnesses:

  1. Bacteria
  2. Viruses
  3. Parasites
  4. Protozoa
  5. Fungi
  6. Prions

Q2: What is the type of contamination in a food establishment?

There are a total of three contaminations in a food establishment:

  1. Chemical: When food produces or comes into contact with toxic chemicals, which can lead to chemical food poisoning.
  2. Physical: When a physical object enters food at some stage of the production or preparation process.
  3. Biological: When food becomes contaminated by living organisms or the substances they produce.

Q3: What symptoms may biological contamination cause?

Symptoms may include:

  1. Sneezing
  2. watery eyes
  3. Coughing
  4. shortness of breath
  5. Dizziness
  6. Lethargy 
  7. fever, digestive problems

Q4: What are the effects of biological contamination on public health?

It may cause allergic reactions such as high-susceptibility pneumonitis and asthma, infectious diseases including flu, chickenpox, etc.

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