Biocontaminants in Occupational Perspectives: Basic Concepts and Methods

ABSTRACT

Biological hazards are major occupational hazards concerned with several issues. These hazards are very dangerous and have to be taken seriously by employers and employees. The present chapter deals with the basic concepts, regulatory aspects, and methods related to the prevention of biocontaminants. The center of attraction of this chapter includes focusing on nosocomial infections, Legionnaires' disease, sick building syndrome, etc. The role of engineering, administrative, workplace hazardous material information, personal protective equipment, standard precautions, and ISO standards for avoiding risks to all types of biohazardous material are mentioned in a comprehensive manner.

INTRODUCTION

Biological hazards can enter the body in several ways. When determining the appropriate protective measures, measures are a clear understanding of how the hazards can enter the body (Stetzenbach et al., 2004). It may be through inhalation (breathing), ingestion (swallowing), injection (puncture), and absorption

  • (through direct contact) (Gomy et al., 2002). The risk is divided into four stages (Figure 5.1):
  • • BSL-1: Agents not known to consistently cause disease in a healthy adult human.
  • • BSL-2: Moderate potential threat to personnel and the environment, including bacteria and virus that cause only mild disease to the human.
  • • BSL-3: Microbes there can be either indigenous or exotic, and they can cause serious or potentially lethal disease through respiratoiy transmission, for example, HIV, H1N1 flu, rabies, SARS, ricketts, tuberculosis, etc.
  • • BSL-4: Dangerous and exotic, posing a high risk of aerosol-transmitted infections. Infections caused by these microbes are frequently fatal and without treatment or vaccines (Quinlan et al., 2010).

A product or a process may become contaminated at the various processes of manufacturing either by inanimate or animate matter. Here, we focus on any product that becomes contaminated by bacteria, viruses, or fungi. It can be the organism itself or its toxins that can be hazardous to human health if inhaled, swallowed, or absorbed into the body. The microorganisms such as bacteria, fungi, viruses, or their toxic products may contaminate through water, air, insects, soil, workers, and failure of good manufacturing process (GMP) (Frick et al., 2000). Several types of biocontaminants are found in the environment. The bacterial biocontaminant maybe Gram-positive or Gramnegative according to the laboratory method of staining by Gram stain. As different types of microbes grow in different environments, various microbial particulates can become a biocontaminant, which can become an indicator that can be monitored (Alii, 2008). Mycotoxins are toxic chemical products of a fungal metabolite that become biocontaminants as fungus affects the biological product being manufactured (Table 5.1).

SOME COMMON DISEASES CAUSED BY BIOCONTAMINANTS

LEGIONNAIRES'DISEASE

The American Legion organized its annual convention in a hotel in 1976. Three days after the convention ended and within a week, more than a hundred participants had been hospitalized due to cough, high fever, and breathlessness along with some other ailments, leading to atypical pneumonia. About a quarter of them died. The Centers for Disease Control and

Levels of biocontaminant risks in nature

FIGURE 5.1 Levels of biocontaminant risks in nature.

Living Sources

Units

Source Examples

Effect on Humans

Lifestyles

Principal Indoor Sources

Bacteria

Spore

T hermo actinomyc es

Hypersensitivity pneumonitis

Saprophytes

Hot water sources

Organism

Legionella

Pneumonia

Facultative parasites

Cooling towers

Product

Proteases

Asthma

-

Industrial processes

Endotoxin

Chills, fevers

-

Stagnant water reservoirs

Fungi

Spore

Alternaria

Rhinitis, asthma

Saprophytes

Outdoor air

Organism

Sporobolomyces

Hypersensitivity pneumonitis

Saprophytes

Damp environmental surfaces

Protozoa

Antigen

Acantliamoeba

Hypersensitivity pneumonitis

-

Contaminated water reservoirs

Organism

Naegleria

Infection

Facultative parasites

Contaminated water reservoirs

Algae

Organism

Chlorococus

Rhinitis, asthma

Autotrophic

Outdoor air

Spores

Antigen

Glycoprotein

Rhinitis, asthma

-

Outdoor air

Volatile

Aldehyde

Mucous membrane irritants

-

Damp surfaces

Toxin

Aflatoxin

Cancer

-

Damp surfaces

Histoplasma

Systemic infection

Facultative parasites

Bud droppings

-

Virus

Organism

Influenza

Respiratory infection

Obligate parasites

Human host

Arthropod

Feces

D ermatopha go ides

Pha go trophic

-

Plant

Pollen

Ambrosia

Rhinitis, asthma

Autotrophic

Outdoor air

Mammal

Saliva

Cat

Rhinitis, asthma

Pha go trophic

Cat

Saliva scale

Horse

Rhinitis, asthma

Pha go trophic

Horse

Prevention investigated the outbreak from all aspects, including the hotel environment. In 1977, they identified Legionella pneumophila, a bacterium that was flourishing in the cooling tower of the air conditioning system of the hotel. The bacteria had spread through the duct system of the air conditioner throughout the hotel rooms. Those affected were the elderly with poor immune status who were inhaling the infected humid air. It normally does not spread through person to person contact (Rom and Markowitz, 2007). Water remained an imperative factor for the growth of microorganisms (Table 5.2).

TABLE 5.2 Water as an Imperative Source for Proliferating Biocontaminants

Outdoor

contaminants

Swamp Coolers

Small Lakes

Fountains

Poorly kept landscaping

Under house crawlspaces

Agricultural storage

Air conditioners

Water softeners

Wooden structures

Drainage ditches

Cooling towers

Compost piles

Industrial HVAC exhaust

Wells or potable water storage containers

Sewer drains

Indoor

contaminants

Improperly placed vapor barriers

Ventilation ducts and insulation

Water-damaged

carpets

Refrigerator pans

Humidifiers

Leaky appliances

Leaky roofs

Subterranean rooms

Leaky plumbing

Ceiling tiles

Air conditioners

Crawlspaces

Bathroom shower and tub

Coldwater pipes

Ground-level cement slabs and walls

Furniture

Wallpapers

Window coverings

Standing water

Wet or damp materials

Hot water tanks

Plants, animals, birds, and humans

Evaporative coolers

Pillows, bedding, and house dust

NOSOCOMIAL INFECTION

Nosocomial infection is also known as hospital-acquired infection (HAI). These infections develop in hospitalized patients who were neither suffering from that disease nor were they in the incubation period when admitted (Table 5.3). This infection has been acquired from a hospital or a healthcare facility. The source of such infection may be exogenous from hospital staff, other patients, or even inanimate objects like bed sheets, linen, contaminated equipment or endogenous from the patient’s own microflora that may have been introduced by an operative or investigative procedure, instrumentation, or during nursing care (Gatchel and Schultz, 2012). The predisposing factors may be contaminated dressing, air, water, food, multidrug-resistant microflora, improperly screened blood and blood products, intravenous fluid, needle stick injury, droplet transmission, etc. The causative organisms may be Gram-positive or Gram-negative bacteria, viruses, fungi, or parasites. Preventive measures include proper sterilization, donor screening, isolation, proper handwashing, use of sterile gloves and gowns by staff, etc. (Schilling, 2013).

TABLE 5.3 Potential Biological Hazards

Biohazard

Disease

Spread

Control

Bacteria

Pink eye

Human-to-human contact

Do not share eye makeup, wash hands

Virus

Hepatitis A

Human-to-human contact

Do not ingest contaminated food or water, avoid direct contact with infected people

Virus

Hepatitis В

Human-to-human contact

Immunization, avoid direct contact with infected people, avoid tattooing and body piercing, dispose of sharps in disposal containers

Virus

Hepatitis C

Human-to-human contact

Avoid direct contact with infected people, avoid tattooing and body piercing, follow standard precautions

Virus

Measles

Human-to-human contact spread by cough and nasal droplets

Immunization, avoid direct contact with infected people

Biofilms are formed when a group of microbes, bacteria, fungus, and protista, adhere to each other on a living or nonliving surface that becomes protected by a layer of the self-generated matrix of extracellular polymeric substance made up of proteins, lipids, polysaccharides, and others. Bacterial biofilms are infectious and are a common cause of nosocomial infections. Biofilms may form on both living and nonliving surfaces (Levy, 2006). So, they may be seen in hospitals or industrial settings as well as in humans or animals, the commonest being the dental plaque affecting teeth and gum. Biofilms are biological systems that are developed by bacteria by organizing into functional community that symbiotically share nutrition, growth factors, and other chemicals and shelter themselves from harmful environmental factors, antibiotics, as well as the host’s immune system, which are essential for their survival. Hence, because of such characteristics, biofilms become adherent to biomedical devices like catheters, prosthesis, ventilators, etc., causing HAIs, which are difficult to eradicate (Wilcock, 2006).

SICK BUILDING SYNDROME

The sick building syndrome describes a condition in which employees or residents experience nonspecific illnesses, like headache, nausea, throat irritation, difficulty in concentration, fatigue, allergies, etc., whose cause cannot be specifically identified (Waldron, 2013). This is often classified as an occupational disease (Table 5.4).

The factors suspected include the following:

i) Biological contaminants like bacteria, viruses, fungi, pollen, etc. These contaminants flourish in stagnant water in humidifiers, ducts, drainpipes, insulations, upholstery, as well as insect droppings.

ii) Inadequate ventilation with little outdoor airflow.

iii) Chemicals from outside like vehicle exhaust, dust, paint, products of combustion, and volatile compounds like pesticides, cleaning agents, etc.

iv) Poor ergonomics, improper lighting, humidity, incorrect acoustics, etc.

The importance of this condition is due to the reduced work efficiency and increased absenteeism among workers, leading to a fall in productivity.

TABLE 5.4 Occupational Hazards

Occupation

Contact Source

Disease

Doctor, dentist, nurse, healthcare volunteer

Blood and other constituents of patients

Hepatitis, cold, flu

Childcare worker

Body fluid of children, diaper, cut

Cold, flu, eye infection, head lice

Food service

Undercooked food

Salmonella, E. coli

Waste disposal personnel

Broken glass, contaminated needle

HIV, hepatitis B, and hepatitis C

 
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