Air Pollution in Gibraltar – a continual problem

in Environmental Insight

During the COVID-19 lockdown I had observed various initiatives being carried out around various parts of Europe and was eagerly looking forward to the measures our Government would implement. 

o far, the only new initiative being implemented has been the temporary closure of Line Wall Road from Saturday to Monday, and this has triggered a public outcry and lots of angry Facebook posts. The environmental groups have welcomed the initiative but it is difficult to see where the benefits for the environment lie. The rerouting of traffic along Line Wall Road is resulting in longer journeys as Line Wall makes for a faster and quicker route for traffic getting from the north to the South, and vice versa. Having to divert to Line Wall Road means that travellers will take longer to make the same journey, use more fuel and create more pollution. The Queensway travellers also encounter heavier traffic and more traffic lights, both of  which mean more slowing down, stopping, idling and then accelerating again. Studies have found that these conditions can lead to a high concentration of particles (up to 29 times higher) than when traffic is free-flowing. More pollution is created during acceleration and braking and the highest levels can be found in areas of frequent braking and accelerations such as slow-moving traffic and speed bumps. 

In Gibraltar, we have wasted an unprecedented opportunity to measure differences in air quality during the COVID-19 lockdown due to a lack of monitoring equipment. The equipment in use currently is old and much of it has fallen into disrepair. Black carbon has not been monitored since the beginning of March this year, and sulphur dioxide since the beginning of May. At the time of writing PM10 is also not being measured, perhaps the equipment has developed a fault and is awaiting repair. Thus we don’t really know how the lockdown and decrease in road traffic affected these pollutants. Similarly, we don’t know whether the decrease of sulphur in marine fuel has led to a decrease in sulphates and sulphur dioxide in the air around Gibraltar. 

One major problem is that in Gibraltar the Government does not monitor real-time PM2.5; the fine particulate matter that have been causally associated with heart attacks, strokes and heart disease; as well as respiratory disease and increased risk of Alzheimer’s Disease. PM2.5 are more dangerous than the larger PM10, the 10 referring to the size of the particles; in this case 10 microns. The finer particles do not drop to the ground as readily as the heavier PM10, so they remain suspended in the air for a longer period and travel for longer distances; sometimes across continents. We do have gravimetric monitoring which measures the amount of PM2.5 collected over a 24-hour period, but the results are not available for months and they don’t give any indication of how PM2.5 levels fluctuate throughout the various times of the day. Real-time monitoring would give us an idea of how levels change throughout the day and could help to identify hot spots of particulate pollution. It could also help to evaluate whether or not measures taken to address pollution are working. However, a disadvantage with the fixed reference monitoring is that they only measure pollution at one location and can miss hotspots. 

One way that researchers and citizen scientists are getting round this problem is by using low-cost pollution sensors. A few years ago, I purchased a variety of low-cost sensors in order to measure the air quality myself. One of these is the PurpleAir sensor that hooks up to a network made up of sensors measuring different sizes of PM, in many parts of the world. The data are uploaded to an online map where you can view your own data and those of all other PurpleAir sensors globally. Last year the Government purchased some low cost sensors of a different make, AQMesh, but the PM2.5 levels they register are always unusually low and never seem to agree with the PurpleAir data or indeed that shown on my other sensors. 

The AQMesh sensors also measure nitrogen dioxide levels and data from the lockdown period has confirmed that much of our air pollution does not come from traffic. The levels of nitrogen dioxide continued to be high at Europort Road near the generating stations and the Rosia Road Clocktower sensor by the shipyard, even when there was very little traffic on our roads. 

Shipping continues to be a major contributor to pollution in Gibraltar. Around 60,000 cases of death due to cardiovascular disease and cancer have been associated with global shipping emissions. Shipping exhaust contains more volatile organic compounds (VOCs) than regular traffic exhaust; around 9% of which include benzene, toluene and xylene. These compounds are naturally found in high amounts in the heavy fuel oil which is used to power the very large vessels and have been regulated in regular motor vehicle fuel because of their harmful impacts on health. 

In a few weeks the Government will present a Bill before Parliament to limit the emissions of black smoke under some circumstances. But black smoke is not the only pollutant emitted from ships. Large vessels bunkering in the Bay run their auxiliary engines which produce ultra-fine and fine PM in the region of 0.2 to 2.5µm. Most of the PM appears to be around 0.4µm which makes them easily inhaled into the deeper parts of the lungs, where they pass through the alveoli into the bloodstream and can trigger inflammation, cardiovascular disease and strokes. Recent research has also linked PM2.5 to Alzheimer’s disease.

One study by NOAA and the University of Colorado found that tug boats emit near 1 gram of soot per kilogram of fuel burned, which is almost twice the amount of soot per amount of fuel used than other commercial vessels. Tankers and container ships emit half this amount when docked and a bit less when they are moving. Soot is known to cause cancer and also contributes to global warming by reducing the reflectance of snow and ice. The problem with tugboats (and bunkering vessels) is that their emissions don’t happen out at sea but out in the Bay where the emissions affect residents living close by. The number of ships bunkering in the Bay has increased over the last two decades. In 1996 the only supplier was Shell with a market of around 250,000 tonnes whereas by 2015 Peninsular Petroleum was supplying 11 million tonnes. This increase in shipping activity has brought a huge increase in pollution, and unfortunately, repercussions on our health. 

In Gibraltar, deaths due to respiratory disease have been increasing steadily at a rate of around 1 to 2% per year (GHA, 2014) and the deaths did not only occur in older people as might be expected; instead they were uniformly distributed across the ages in the over-50s. In the year 2000, deaths from respiratory disease made up only 6 % of total deaths but by 2012 it ranked first place in cause of death. It is now known that pollution increases the vulnerability of the respiratory system to viruses such as influenza and to bacterial pathogens increasing the risk of pneumonia. 

Back in the winter of 2017/2018, over 500 patients were seen in A&E during just one week in late December and unfortunately there was one death as a result. At the time the GHA Medical Director had said that the numbers of patients being seen and admitted with influenza was the highest they had seen for many years. 

The COVID-19 lockdown has illustrated how a reduction in air pollution is possible when traffic and industry are curtailed; and how respiratory infections can be killers, especially when combined with particular risk factors. In Gibraltar, air pollution is one of the risk factors that already seems to be having an effect on the population’s respiratory health. It’s time that our Government stop ignoring the evidence and act upon it. 

What can I do?

As citizens we can – and should – all do our part to reduce the pollution we create by using active transport such as cycling and walking or taking the bus wherever possible; and employing smoother driving techniques such as avoiding unnecessary accelerations. But we also need to write or email our members of Parliament asking them to take stronger measures against the main contributors to Gibraltar’s pollution which are out of our control such as shipping, the ship repair yard and power generation. Together we can all play a part in improving our air quality and invest in the future health of our families and community. 

Follow @PollutionWatchGibraltar on Facebook for regular updates 

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