Statement on PHE Southall Waterside Risk Assessment

Public Health England (PHE) have now published their fourth health risk assessment of air quality monitoring results which identifies that there is ‘unlikely to be a direct toxicological risk to the health of the nearby population from the levels of VOCs (volatile organic compounds) detected’.  This fourth report covers 10 May 2019 to 6 January 2020. 

PHE have compared the monitoring data to available health-based air quality guidelines and standards or assessment levels.

The report acknowledges that odours can cause annoyance and it is likely that the surrounding population have noticed odours, but PHE also identify that odours in themselves are not harmful to health. 

The report notes that there is a continued decrease in VOC concentrations following closure of the soil treatment hospital at the beginning of April 2019. 

The monitoring data has identified that the majority of identified chemicals were lower than the relevant air quality guidelines or standards.  Some chemicals have been recorded above the point at which most people can detect the smell, but these exceedances have been for short periods and remained below levels likely to cause acute, short-term or long-term health impacts.

Chemicals recorded as being intermittently above guidelines or standards also remained below levels likely to cause acute or short-term health impacts. These were benzene, trichloroethylene, trimethylbenzenes, and 4-isopropyltoluene.  *Naphthlene levels were regularly recorded above the guideline values but PHE concluded that "considering that the off-site concentrations are falling to beneath the MRL (mininal risk level) and assuming that this trend continues, the detected levels of naphthalene do not represent an immediate risk to health and the risk of any long-term health impacts is likely to be low".

The report identifies that monitoring stations are positioned on the site boundary and the concentrations of the compounds in the air will have diluted further before reaching the surrounding population, reducing the potential health risk.  It also identified that the off-site monitoring stations recorded concentrations at beneath the minimal risk level for health. 

The report concludes that while improvement is welcome, it is recommended that appropriate mitigation measures and monitoring are in place.

The council has committed to ensuring the developers continue to have all appropriate mitigation measures in place.

The council has commissioned the services of an independent consultant (Ricardo-AER) to develop a low emissions strategy (LES) for Southall Waterside. Work on this began in August 2020 and is expected to be completed by December 2020.

The low emission strategy is a document that will set out specific measures and figures to achieve the lowest possible emissions from the development when built (residential buildings/shops etc) and when various forms of transport are used across the site.

The full report can be seen here

The council wants to hear from anyone experiencing problems and ask they contact us on 020 8825 8111 so we can investigate. Anyone concerned about their health should contact their GP or call the NHS on 111.

Background:
PHE have previously completed three interim risk assessments, the first of which was based on air quality monitoring undertaken between 1 June and 25 September 2018, the second was based on air quality monitoring undertaken between 25 September and 12 December 2018 and the third was based on air quality monitoring undertaken between 12 December 2018 and 10 May 2019. This latest report and risk assessment has been updated following receipt of additional air quality monitoring data undertaken between 10 May 2019 and 6 January 2020.

*Statement updated on 7 October 2020 to include information on naphthalene. Naphthalene is present in the environment from various sources such as vehicle exhaust, use of solvents or creosote. The main route of exposure is inhalation, especially in the vicinity of heavy traffic, petrol stations and oil refineries. Naphthalene is used in moth repellents and has a distinctive smell.