There are several options for the treatment of equine asthma, in addition to environmental modifications. Human metered dose inhalers (MDI) have been used in horses with equine asthma for many years, but many people are unaware of their surprisingly large carbon footprint.
Pressurised metered dose inhalers (pMDI), such as Ventolin or Clenil Modulite inhalers, contain hydroflourocarbon (HFC) propellants that are very powerful greenhouse gases. Inhalers containing chloroflourocarbon (CFC) propellants, which damage the ozone, were phased out in the 1990s, but the HFCs are still thousands of times more potent than carbon dioxide and contribute significantly to global warming. A Ventolin EvohalerTM has a carbon footprint of 28kg per inhaler, equivalent to the direct greenhouse gas emissions of driving 175 miles in a small car. It is reported that the propellants in pMDIs are responsible for an estimated 3.5% of all NHS emissions.
Empty pMDIs contain residual propellants, which is a concern if they end up in landfill where the residual HFC propellants may get released into the atmosphere. However, these HFCs are destroyed if the used inhalers are incinerated. It has been estimated that, if every inhaler user in the UK returned all their inhalers to pharmacies for disposal by incineration, this could save 512,330 tonnes of carbon dioxide per year – that's the same as a VW Golf car being driven round the world 88,6060 times.
There are several alternatives to pMDI for the treatment of equine asthma, many of which have clinical, as well as environmental benefits. These include systemic medications, nebulised medications and dry powder/soft mist inhalers (such as the Aservo Equihaler, licensed for use in horses in the UK).
Dry powder and soft mist inhalers do not contain any propellant and therefore have a significantly lower carbon footprint than pMDIs. Additionally, Boehringer Ingelheim state that their Aservo Equihaler is made from 50% recycled materials and that the plastic components can be recycled with TerraCycle.
Many horses with equine asthma may have been managed for many years using pMDIs, but, given the large environmental cost of these as well as potential clinical benefits of alternative treatments, it may be worth considering other options.
References
Greener practice: Asthma care and inhalers
Wilkinson, A. and Woodcock, A. (2022) The environmental impact of inhalers for asthma: A green challenge and a golden opportunity. British Journal of Clinical Pharmacology 88, 3016–3022.
Recycle now
Equihaler recycling information