Dabs, Vapes and Thirdhand Smoke: An Update on Environmental - - PDF document

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3/5/2019

Dabs, Vapes and Thirdhand Smoke: An Update on Environmental Exposure to Tobacco and Marijuana

Suzaynn F. Schick, PhD

Conflicts and Acknowledgements

• No conflicts to disclose
• Funding from the California Tobacco-Related Disease

Research Program, grants 20PT-0184, 21ST-011, 24RT- 0039, 28IR-0049 and 28PT-0081

What is Thirdhand cigarette smoke? The 3 R’s

Chemicals in cigarette smoke that:

• Remain on surfaces and in dust
• Re-emit back into the gas phase
• React with other chemicals in the environment to make new

chemicals

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What is smoke?

• Gases
• Particles and droplets of oils and waxes

(Tar)

• 10% of secondhand smoke is tar

Thirdhand Smoke starts with Tar

Remain

• Tar chemicals stick to surfaces before they can be

removed by ventilation

• Walls, carpet, dust, people…
• Tar absorbs into porous materials
• Tar contains nicotine and many toxins and

carcinogens

• Nitrosamines
• Polycyclic aromatic hydrocarbons
• Persistence increases exposure time

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Re-Emit

• Combustion forces tar chemicals (normally solids or

liquids) into the air

• Tar cools, condenses and sticks to surfaces
• Once on a surface, each chemical reaches

equilibrium

• Fraction in the air depends on the chemical

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React

• Where there are chemicals, there are chemical reactions
• Which reactions do we know about?
• Nicotine + nitrous acid = NNK
• Carcinogen
• Nicotine + ozone = formaldehyde
• Carcinogen
• Tar + ozone = ultrafine particles
• Can cause heart and lung disease

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PubMed citations in environmental smoke research

• “Tobacco smoke pollution”
• 12,876
• “Secondhand tobacco smoke”
• 2135
• “Thirdhand tobacco”
• 77
• “Marijuana smoke pollution”
• 62
• “Secondhand marijuana smoke”
• 23
• “Thirdhand marijuana”
• 2

Cannabis products

• Unfertilized female flowers (buds)
• THC content = 10-30%; local dispensary average ≅ 20%
• Concentrates
• 40-98% THC
• Physically separated trichomes (hash)
• Hydrocarbon extracts (butane hash oil)
• CO2 extracts
• Heat/pressure extracts
• Cartridges and vape pens
• Filled with concentrates
• Edibles
• Most use a cannabis-infused fat or oil with 5 - 10% THC
• Tinctures
• Most are oil-based, not alcohol
• Topicals

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Modes of use

• Combustion
• Cigarettes
• Pipes & water pipes
• Blunts
• Aerosolization
• Vaporizing flowers
• Vaporizing concentrates
• Dabbing
• Vape pens

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Sources of Cannabis Emissions

Material Activity Temperature Mass per use Flowers, concentrates Smoking 400-900° C 0.2-2 g Concentrates Dabbing 175-815° C 0.1-0.5 g Flowers, concentrates Vaporizing 150-220° C 0.1-2 g Whole plant Indoor grow Ambient 0.5-200 kg Flowers, trim Extraction Varies with method 0.2-200 kg Flowers, trim Decarboxylation, cooking 115° C 0.02-20 kg Edible preparations Eating 37° C 0.1-2 g Topical preparations Rubbing on skin 37° C 0.1-2 g

A Natural Experiment: 2 Dispensaries with different consumption policies

• Dispensary 1
• Vaporizing, dabbing and vaping
• Only devices provided by dispensary are permitted
• Estimated room area = 14,000 ft3 (400 m3)
• Central HVAC w/ 2 vents + 4 window AC units
• Dispensary 2
• Smoking, dabbing and vaping
• Provides dab rigs, bongs and lighters, customer devices permitted
• Estimated room area = 16,000 ft3 (450 m3)
• One central HVAC vent (?), one small air circulating fan

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Summary: Dispensary 1 vs Dispensary 2

Mass per source 1 Unknown 2 Number of sources 1 < 16-18 X 2 Air exchange rate 1 > 2 Particle deposition rate 1 Unknown 2

• Dispensary 1 Particle concentration was 8 X less than Dispensary

2

• Particle concentration depends on:

What would the air quality index be in these dispensaries?

• The US Air Quality Index (AQI) was designed for outdoor air
• It integrates 6 pollutants into 1 value
• PM2.5

Nitrogen dioxide PM10

• Ozone

Sulfur dioxide Lead

• Carbon dioxide
• AQI numbers do not equal pollutant concentrations
• There is a different threshold scale for each pollutant
• PM2.5 AQI thresholds are for 24 hour averages

Health risks of PM2.5 exposure

• Acute (minutes to days)
• Increased risk of myocardial infarction
• Exacerbation of respiratory disease (asthma and COPD)
• Chronic (months and years)
• Atherosclerosis
• Myocardial infarction and stroke
• Chronic obstructive pulmonary disorder (emphysema)
• Asthma
• Cancer
• …

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Question 1:

The California Medicinal and Adult Use Cannabis Regulation and Safety Act allows consumption of cannabis in all the following places, except:

a) In licensed retail stores and microbusinesses, with on site

consumption permits

b) At special events at county fairgrounds and agricultural

associations

c) Outdoors, in public places d) In private residences, with the owner’s permission

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Question 2:

Please select the cannabis consumption methods that can increase airborne particle concentrations:

a) Smoking b) Vaporizing and Vaping c) Dabbing d) All of the above

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Question 3:

Acute exposure to PM2.5, at any concentration, is associated with?

a) Endothelial dysfunction, increased risk of myocardial

infarction

b) Decreased FEV1, increased risk of bronchitis c) Fever d) Increased risk of lung cancer

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