Biological aerosols are aerosols of living organisms. They include bacteria, viruses, fungi, and protozoa. Biological aerosols are capable of causing disease in humans and animals. Inhalation is the most common mode of transmission for biological agents.
Biological agents can be dispersed into the air by a number of mechanisms, including coughing, sneezing, talking, or through mechanical ventilation systems. These particles can remain suspended in the air for long periods of time and can be transported over long distances. Depending on the size of the particle, they can remain airborne for hours to days.
The Centers for Disease Control and Prevention (CDC) defines four categories of bioaerosols: infectious (pathogenic), non-infectious (potentially allergenic), toxigenic (poisonous), and nontargeted (environmental). Infectious bioaerosols contain pathogens that can cause infections when inhaled by humans or animals. Non-infectious bioaerosols do not contain pathogens but may still cause allergic reactions in some people. Toxigenic bioaerosols contain toxins that can be poisonous if inhaled. Nontargeted bioaerosols are environmental contaminants that may be present in indoor or outdoor air but are not considered harmful to human health at typical exposure levels.
Bioaerosol sampling is a technique used to collect airborne particles so they can be analyzed to identify the presence of specific microorganisms or toxins. A variety of samplers exist that differ in how they collect particles from the air; each has advantages and disadvantages depending on the application. The most commonly used samplers for collecting biological aerosols are impingers, filters, centrifuges, and liquid media collectors such as culture plates or agar plates .
Aerosolization is a process where liquids are converted into small droplets or solid particles that suspend in the air . This process often occurs naturally – think about sea spray , fog , mist , clouds , raindrops , snowflakes . However , it also happens during many industrial processes like spraying paint or using cleaning products . When done intentionally , this is called “ engineered aerosolization ” and there are many different ways to produce an engineered consumol . One method involves using compressed gas to force a liquid through a small hole which breaks up the liquid into tiny droplets ; another method uses ultrasonic waves . There is also evidence that some infectious diseases – like influenza – may spread via contaminated surfaces and objects rather than through direct contact with respiratory secretions from an infected individual
Biological warfare dates back centuries ; however , it was not until World War I that large – scale use occurred . During WWI both sides utilized various forms of bioweapons including bacteria ( e . g., anthrax ) and toxins ( e . g., mustard gas ). The effects were devastating with thousands killed outright and many more suffering long-term effects ; however , due largely to their indiscriminate nature these weapons were eventually banned under international law More recent examples include letters laced with anthrax spores sent through US mail in 2001 which resulted in 22 confirmed cases ( 5 fatal ) In 2015 – 2016 an outbreak Zika virus occurred primarily Brazil which then rapidly spread throughout South America as well as Puerto Rico As these examples illustrate biological agents have been weaponized historically as well as currently pose significant public health threats both domestically within countries as well cross – border
Despite great advances medical science understanding pathogenesis viruses other microorganisms much work needs still be done develop effective treatments preventions Many questions surrounding potential new outbreaks often go unanswered until after event passes making difficult prepare adequately For example SARS outbreak 2002 caught everyone off guard only identified after fact had already begun pass Through collaboration between multiple disciplines will critical increase knowledge base needed anticipate future events better protect populations