HOW WHISKY MAKING AFFECTS HEALTH

 Non-methane volatile organic compound emissions
from malt whisky maturation

Review of the human health and environmental impacts of non-methane volatile organic compound emissions from malt whisky maturation facilities

DIRECT INHALATION OF ETHANOL

Impacts of some individual species of non-methane volatile organic compounds (NMVOC) such as benzene and formaldehyde have been identified previously at concentrations close to typical ambient levels for public exposure. However, less research has been conducted into the harm from human exposure to typical ambient concentrations of ethanol or other likely evaporative emissions from the storage of whisky. The majority of studies performed on the impacts of ethanol do not concern the inhalation of ethanol but rather the consumption of it. It should be possible to estimate the quantity of alcohol inhaled annually by people living close to the bonded warehouses if ambient concentration data were available. Unfortunately, monitoring of ambient concentrations of ethanol does not occur. The International Agency for Research on Cancer (IARC) states, however, that:

"There is no safe level of alcohol consumption for cancer risk, and all types of alcoholic beverages, including beer, wine, and spirits, are linked to cancer risk, regardless of their quality and price. The risk of developing cancer increases substantially when more alcohol is consumed."

The NHS (2022) provides information for the public on the impacts of different levels of alcohol consumption. The following points are pertinent here:

·     If you drink less than 14 units a week, this is considered low-risk drinking. It's called ‘low risk’ rather than ‘safe’ because there's no safe drinking level.

·    The type of illnesses you can develop after 10 to 20 years of regularly drinking more than 14 units a week include: mouth cancer, throat cancer and breast cancer, stroke, heart disease, liver disease, brain damage, damage to the nervous system. Additionally, multiple studies conclude that alcohol consumption can make your mental health worse with strong links between alcohol misuse and self-harming, including suicide.

·    The effects of alcohol on your health will depend on how much you drink. The less you drink, the lower the health risks.

That there is no safe drinking level indicates that any exposure has potential for harm, even amongst those that do not drink at all.

When alcohol vapour is inhaled, it is thought to bypass initial metabolism and instead be rapidly transmitted to the brain via the arterial blood. A literature review of the impacts of inhalation found that results were inconclusive due to a lack of studies in this area. It may be possible that inhalation of alcohol vapour increases the propensity for alcohol addiction to develop, as shown in trials on mice. It is unclear if a similar effect may be seen in humans, particularly in vulnerable populations who are already at an elevated risk of developing substance addictions.

Some studies have also examined the impacts associated with inhalation of alcohol vapours produced from the use of alcohol-based hand sanitisers. The US Food and Drug Administration (FDA) warned that the vapours from alcohol-based hand sanitisers can cause symptoms such as headache, nausea and dizziness. However, it is worth noting that such products may not purely contain ethanol, but instead are likely to produce vapours that contain a variety of alcohols. Most commercially available hand sanitisers contain 70% ethanol and isopropanol. It is therefore unclear whether any conclusions drawn from these studies will also apply to inhalation of ambient ethanol from Scotch whisky production.

Public Health England list the possible side effects of acute exposure to ethanol vapours (PHE, 2015). These include irritation of the throat and difficulty breathing at 9,400,000 μg/m3, and lacrimation and coughing at 30,000,000 μg/m3. At higher concentrations, central nervous system depression may occur. Emergency response planning guideline (ERPG) values have also been provided in the US, which are designed to anticipate health effects to airborne chemical concentrations. The maximum airborne concentration below which it is believed that nearly all individuals could be exposed for up to 1 hour without experiencing other mild transient adverse health effects is listed as 3,456,000 μg/m3. The concentration below which it is believed nearly all individuals could be exposed to for up to 1 hour without experiencing irreversible or serious health effects is 6,336,000 μg/m3. These are short term exposure limits, and therefore it is still unclear what the effects may be due to long term ambient exposure for those living in the vicinity of Scotch whisky facilities. Due to the typical accumulation of exposure effects, long-term exposure limits are generally set at significantly lower concentrations than short term limits. For ethanol, this may not be as relevant as for other pollutants, as ethanol does not accumulate in the body (OECD, 2004), and therefore the greatest risk is likely to be from short term exposure to high concentrations.

The American Conference of Governmental Industrial Hygienists (ACGIH) is cited by the Indiana State Department of Health (2019) as concluding that airborne ethanol has chronic non-cancer health effects at concentrations of 2,200 μg/m3 or higher. ACGIH refers to a higher level for effects (though possibly for cancer, specifically), giving a Threshold Limit Value – Short Term Exposure Limit (TLV-STEL) of 1,880 mg/m3 (1,000 ppm), citing ethanol as a confirmed animal carcinogen.

Study/Organisation	Ethanol Concentration	Human Health Risk	Groups Affected
PHE	9,400,000 μg/m3	Irritation of throat and difficulty breathing	All
PHE	30,000,000 μg/m3	Lacrimation and coughing	All
ERPG	3,456,000 μg/m3	Mild transient adverse health effects	All
ERPG	6,336,000 μg/m3	Irreversible or serious health effect	All
ACGIH	2,200 μg/m3	Chronic non-cancer health effects	All

In the UK, the Health and Safety Executive (HSE) sets essentially the same workplace exposure limit of 1880 mg/m3 (1,880,000 μg/m3), though describes it as a long-term limit (8-hr reference period, versus 15 minutes for short term) (HSE, 2020).

Due to the lack of monitoring of ethanol concentrations, it is not possible to compare these exposure limits to the concentrations individuals may be exposed to. However, the estimated concentrations from the largest emitting bonded warehouse (23,000 μg/m3) does exceed the exposure threshold provided by the ACGIH for chronic non-cancer health effects. But occupational limits tend to be many times higher than those established for exposure of the public. Limits for members of the public set under clean air regulations are all significantly lower than workplace exposure limits to pollutants where both such limits exist. The ambient air regulations in the UK do not address ethanol concentrations specifically.

Converting atmospheric concentration to an estimate of alcohol consumption, and adopting the position that there is no safe level of alcohol consumption, we could generate an estimate of increased cancer incidence following the approach used for the Global Burden of Disease Initiative referring to the ‘Cancers Attributable to Alcohol Tool’ which may facilitate analysis. Quantification may be possible for some other effects such as stroke, but unlikely. Quantification could either describe a change in risk (e.g. from X cases/100,000 people/year to Y cases/100,000 people/year), or the additional number of cancers if the affected population is known, though this number is likely to be very small indeed given the obtained result.

Information on the website of the European Chemicals Agency (ECHA, 2022) states that ethanol: can cause damage to organs, is toxic if swallowed, may cause cancer, is toxic in contact with skin, is toxic if inhaled, causes serious eye damage, and causes skin irritation. However, this information is based on all exposure pathways, including ingestion. Inhalation, even in areas where ethanol concentrations are comparatively high, does not seem likely to be a major pathway.

NHS guidance (2022) is not to drink more than 14 units of alcohol per week. Intake via inhalation is estimated to be less than 1% of this for the cases where exposure is to concentrations of 800 μg/m3 or less. However, in the highest concentration zone, inhalation accounts for 2% and 10% of the weekly maximum for the resting adult and elite male athlete, respectively.

Exposure to emissions of ethanol from whisky production appears in most situations likely to lead to only a small increase in exposure to ethanol. No evidence has been identified to indicate that this could cause acute effects on the population. However, the analysis presented here should be seen in the context of:

1. Exposure to these emissions is additive to other exposures. Even amongst those who do not consumer alcohol deliberately there is exposure from food and drink such as bread and orange juice.
2. There are indications that low level exposure increases vulnerability to a range of chronic diseases.
3. Exposure of the public to emissions from whisky production is not voluntary.
4. Exposure would affect all age groups.

There are limited studies on the direct inhalation of ethanol particularly beyond the fenceline of maturation and production facilities, however given there is no safe drinking level of alcohol then an element of risk remains. While it is likely that the impact on human health beyond the fenceline of Scotch whisky production facilities as a result of direct inhalation of ethanol is likely to be minor, monitoring of the actual ethanol concentrations close to the larger bonded warehouses is recommended. Information on the website of the European Chemicals Agency (ECHA, 2022) states that ethanol: can cause damage to organs, is toxic if swallowed, may cause cancer, is toxic in contact with skin, is toxic if inhaled, causes serious eye damage, and causes skin irritation. However, this information is based on all exposure pathways, including ingestion. Inhalation, even in areas where ethanol concentrations are comparatively high, does not seem likely to be a major pathway.

Baudoinia Compniacensis

Baudoinia Compniacensis is a sac fungus which thrives in habitats with a high concentration of airborne ethanol, such as outside or near distilleries, bonded warehouses or commercial bakeries. In appearance, the fungus forms black crusts on the façades of buildings where conditions are favourable and it uses ethanol for carbon nutrition as a source of calories. Baudoinia Compniacensis is also known for its ability to withstand high temperatures with warm environments even increasing spore germination. As a result, the fungus is able to form colonies on the outside of buildings involved in whisky production as well as in the vicinity of those buildings if ethanol concentrations are high enough to sustain this.

A review of literature relating to the ethanol concentrations to sustain the growth of Baudoinia Compniacensis has produced inconclusive results. Research conducted by the Indiana State Department of Health Environmental Public Health Division in 2019 did not find any reports of health risks from short or long-term exposure to Baudoinia Compniacensis.

Further investigation into the ethanol concentrations with which Baudoinia Compniacensis grows is required. Ethanol concentrations close to Scotch whisky facilities will likely be greater either close to the larger facilities that emit the greatest quantities of ethanol, or in locations where air flow is reduced, for example in urban areas. In such areas, Baudoinia compniacensis growth is anticipated to be the most extensive. In addition, a watching brief should be maintained for any future studies that demonstrate if there are any human health impacts of Baudoinia Compniacensis.

Ozone Formation

Photochemical reactions between NMVOCs (including ethanol) and NOx can form ground-level ozone. Therefore, NOx concentrations must also be considered when trying to understand the extent of ozone formation from NMVOCs. The reaction pathways between NOx and NMVOCs to produce ozone are complex, but in general ozone formation will be limited by whichever pollutant appears in the lowest concentrations in the atmosphere. Exposure to ozone linked to VOC releases may have the following effects:

  • Mortality
  • Respiratory hospital admissions
  • Cardiovascular hospital admissions
  • Damage to ecosystems (crops, forests, etc.)
  • Damage to livestock production

Premature deaths in the UK attributable to exposure to ozone were estimated to be 880 in 2019 (EEA, 2021b). The same study calculated the estimated years of life lost for the same year, which was 15 years of life per 100,000 inhabitants. The study covered most European countries, and it ranked the UK as having the third lowest relative impacts on health from ozone exposure in Europe. The two countries with the lowest relative impacts on health were Iceland and Ireland, reflecting both their northerly latitudes and prevailing wind directions that lead to reduce transboundary input compared to other European countries. Ozone production at low altitudes requires sunlight, and countries with the greatest relative health impacts were all in the Mediterranean region. Ground-level ozone concentrations are seasonal and highly episodic, with concentrations varying significantly month to month and year to year.

Scottish Monitoring Network Data

Alongside the ozone monitoring network, monitoring relating to nitrogen dioxide (NO2) concentrations can also be considered to gain an understanding of the drivers for the formation of ozone in Scotland. There is some monitoring of NMVOCs, but not those specifically related to the whisky industry. Any monitoring of ethanol concentrations associated with Scotch whisky production that takes place will be informal, and likely only monitoring concentrations within the warehouse for compliance with health and safety standards for the exposure of workers.

Across Scotland, there are 11 air quality monitoring sites which measure exceeds of the Air Quality Strategy Objective (AQSO) for ozone; almost all of the monitoring sites in Scotland recorded exceeding of the AQSO for ozone. It was found that there is variation in the ozone concentrations recorded at urban and rural locations. Ozone monitors in rural locations recorded a greater number of incidences than urban locations. Therefore, it can be concluded that ozone concentrations are generally higher in rural areas than within towns and cities. This is due to the complex nature of the interactions between ozone and nitrogen oxides. Ground-level ozone reacts with nitric acid (NO) to produce NO2 and oxygen, and therefore reducing the concentrations of ozone. NO is emitted from road transport and so NO concentrations are typically higher in urban areas. This means that NO is more readily available to react with ozone to produce other gases. Those living in rural areas are therefore at a greater risk of being exposed to elevated concentrations of ozone.

Ozone formation is highly dependent upon meteorological conditions, which are likely to have a greater impact on ozone concentrations than the emissions from the Scotch whisky industry. That being said, Scotch whisky production contributes significantly to the total NMVOC emissions in Scotland which may form ozone. Therefore, while the impact on human health of Scotch whisky production as a result of ozone formation is likely to be low, further studies are required to fully verify this impact.

Secondary Aerosol Formation

Secondary aerosols are produced from interactions between VOCs and other molecules in the atmosphere. When VOCs are oxidised they produce secondary organic aerosols (SOAs) which may then form tertiary aerosols through further reactions. First-generation products are mostly hydroxyl, carbonyl, hydroxycarbonyl, hydroperoxide and peroxynitrate. Small oxygenated compounds, such as ethanol, have a low propensity to form SOAs. There are no studies concerning the specific make-up of the SOAs produced from the Scotch whisky production process.

Emissions from Scotch whisky may also form secondary inorganic aerosols (SIAs). SIAs consist of a mixture of components such as sulphates, nitrates, black carbon and mineral dust and are part of the particulate matter (PM) in the atmosphere. Smaller particles in the PM2.5 fraction can be carried over long distances by wind before settling elsewhere. Consequently, the secondary formation of PM2.5 as a result of the Scotch whisky industry will not have a purely localised impact. Given the complexity of the formation pathways and the wide variety of aerosols which could be formed, assessing the human health impacts of SIAs and SOAs produced from Scotch whisky emissions will be difficult. It is still unclear what aerosols would be produced from ethanol emissions and the quantities of these aerosols produced.

No studies could be found regarding the creation of secondary aerosols from ethanol production. Given the complexity of the formation pathways and the wide variety of aerosols which could be formed, determining the associated impacts on human health were not possible at this time. Although the health impact is likely to be minor or even negligible, judgment cannot be made as to the likely severity of the human health impacts from aerosol formation once the ethanol is emitted into the atmosphere without dedicated modelling.