Different types of masks and their uses.

1. DR ARUNEEMA BARDHAN
ASSISTANT PROFESSOR
BASIRHAT COLLEGE
BASIRHAT, NORTH 24 PARGANAS, WEST BENGAL, INDIA
UNMASKING THE MASK IN THE
COVID-19 SITUATION

4. Transmission of Coronavirus(SARS CoV-2)
• Between family members
• Intimate contact with asymptomatic carriers
• Intimate contact with infected patients
– through nasal fluids
– saliva
– respiratory secretions
– direct contact

5. Generation of salivary
droplets
• Coughing
• Sneezing
• Talking in close proximity

6. Generation of Saliva Droplets
• 1 normal exhalation-generates saliva droplets reaching 1
metre in air
• 1 cough→3000 droplet nuclei=amount produced during 5
minutes talk
• 1 sneeze→40,000 saliva droplets reaching several metres
in air

7. nCoV Load in Saliva/Oral secretions
• Aerosols
– suspensions of particles in air
– size-.001µm-100µm
• Large droplets
– dia >60µ
– quickly settle from air
• Small droplets
– dia≤ 60µ
– evaporate into droplet nuclei in favourable environment
– potential for long-distance aerosol transmission
• 3.3x106 RNA copies/ml(ranging from 9.9x102-1.2x108
copies/ml)

8. Aerosol Transmission
• Whether saliva droplets
can travel long distances:
-how
long saliva droplets can
reside in air
• Biological decay-how
long pathogen(virus) in
saliva droplets remain
infectious

9. • People can transmit COVID-19 to others
without showing no signs or symptoms
• Widespread use of face masks slows the
spread of virus
• Use simple cloth face covering when in public
places

10. Types of Face Masks
• Function wise:
– Comfort mask
– Surgical face mask
– Surgical respirator
– Particulate respirator
• Usage wise:
–Disposable
–Reusable

11. ERGONOMIC REQUIREMENTS OF MASKS
• Should be breathable and have less breathing resistance
• Loosely cover mouth and nose
• Made of soft materials and comfortable to wear
• Should be light in weight

12. Surgical Masks
• Loose-fitting, disposable, create physical barrier between
mouth/nose of wearer and potential contaminants in the
environment
• Prevents patients from direct transmission of infectious
agents from healthcare professionals
• May be 2 ply, 3 ply or 5 ply

13. Difference between masks and respirators
Surgical masks
• Not PPEs
• Prevent droplets being
expelled into environment
by wearer and protect
patients and operative
sites
Respirators
• Are PPEs
• Used to reduce potential
contact of wearer to
airborne hazardous
contaminants

14. PARTICULATE RESPIRATORS
• Filter particles from air, help to reduce number of particles
or germs the wearer breathes in
• Ideal for protection from PM 2.5
• Secured tightly to face with 2 head straps and an
adjustable nose clip to allo custom fit.
• Approved by NIOSH/ISI

15. Dust Masks
• Prevent inhalation of dust in air and protect lungs-dust is
captured on outside of mask
• Limitations:
– leak if they don't fit
– don't filter out chemical vapors
– may not be suitable for highly toxic dusts

16. Reusable (Fabric) Masks
• Adjustable elastic loops
• Give excellent seal and
nose fit
• Light weight and
comfortable
• Available in all sizes
• Can be homemade
• Washable and reusable
upto 3-4 months

17. Source:[facebook.com/goldenhelix2015/posts/965391937216347]

18. References
• med.stanford.edu/news/all-news/2020/06
• https://www.medrxiv.org/content/10.1101/2020.03.09.20033217v1.full.pdf
• https://www.weforum.org
• https://www.cdph.ca.gov
• https://www.who.int/emergencies/diseases/novel-coronavirus-2019
• https://www.int/health-topics/coronavirus#tab=tab_1
• https://www.nature.com/articles/s41368-020-0080-z#ref-CR8
• https://www.nature.com/articles/s41368-020-0080-z#ref-CR40
• slideshare.net/muralikrishnan71697092/respiratory-protection-face-masks-
and-respirators
• 3mindia.in/3M/en-1N/safety-in/stories/full-story/
• academic.oup.com/cid/article/