Air pollution, human health and shipping's role in reducing particulate matter

The webinar was the second in Riviera Maritime Media’s Maritime Air Pollution Webinar Week, part of our ongoing series of webinars, held in association with Exhaust Gas Cleaning Systems Association (EGCSA).

Attendees heard from EGCSA director Don Gregory, John Murlis, a consultant formerly with the UK Government’s Environment Agency, and University of Naples professor of unit operations Francesco di Natale.

The panellists were in consensus on the point that shipping is a major contributor to port and coastal air pollution and has an adverse impact on human health in port communities. The particulate matter (PM) contained in shipping exhaust is a major contributor to poor health outcomes, having a detrimental effect on human cardiovascular systems and people’s susceptibility to respiratory diseases such as asthma and coronaviruses.

Presenters called on the shipping industry to make faster progress on and to prioritise application of technology to remove PM and volatile organic compounds (VOCs) from shipping exhaust gas emissions within the next five years. The data on the impacts of the emissions is clear and, inevitably, shipowners will be required by regulation to undertake abatement measures, the panel said.

Many shipowners have switched from high sulphur heavy fuel oil (HFO) to low sulphur marine gasoil under the terms of the recently implemented IMO Marpol Annex VI regulations. While the switch is aimed at reducing sulphur oxide emissions, diesel fuels remain major contributors to port air pollution and poor human health.

In his opening remarks, Mr Gregory pointed to the steps the shipping industry has taken to reduce sulphur and nitrogen oxide emissions, and called on the industry to do more to abate PM and other pollutants.

“Exhaust gas cleaning systems reduce SOx levels lower than compliant fuel and remove other pollutants and condensed gaseous pollutant compounds,” he said.

“Future scrubber technology could include the removal of ultra-fine particulates, black carbon, while providing the benefit of lower overall CO₂ emissions,” Mr Gregory explained. He asked ports to reconsider their bans on open-loop scrubbers because, he said, they appear to be prioritising “unsubstantiated impacts on water quality” over improvements in air quality.

Mr Murlis elaborated on the impact on human health from marine pollution, outlining the evidence in support of PM and black carbon pollution as major factors in poor health outcomes in coastal communities.

He presented studies from the World Health Organisation (WHO) proving total pollution was the largest factor on excess human mortality, over what is normally expected. It has a bigger impact than smoking and alcohol intake.

Also, WHO has proven air pollution is the only one of the top five risk factors that is not under personal control. It can cause “cardiovascular disease, chronic respiratory disease, cancer, diabetes, and mental and neurological conditions”.

“Shipping has a major effect on human health. And diesel engines are a major contributor to that, with PM a major concern” said Mr Murlis. “If we improve air quality by reducing emissions and in particular diesel emissions, we will get improved health outcomes.”

These health benefits include less susceptibility to viruses such as Covid-19, according to professor Francesco di Natale. He explained how toxic diesel emissions are to human health as particles can enter the blood stream through the lungs and then infiltrate brain, heart, kidneys and liver. He also called on shipping to act faster to reduce PM and VOC emissions, not just on cutting SOx.

“Fuel switching is not an option to reduce PM, or components of PM,” Prof di Natale said, adding shipping should not ignore the impact of VOCs.

“Although it will be challenging, we need to introduce more exhaust gas cleaning systems to ships to really allow compliance with the other sectors,” he said.

However, according to polls of the webinar attendees, technology to abate PM and VOCs in exhaust gas emissions still needs further development and commercialising.

When asked ’How much time do you think is needed for EGCS providers to put on the market off-the-shelf units to control diesel particulate matter on both a weight and number metric?’, only 4% said they felt the technology was ready. Around 52% said it was three years away, 22% said five years away and 22% more than five years away.

When asked how long it would be before VOC control technology is commercially available, 40% of the audience said more than five years. Another 27% said five years, 13% said three years and 20% said VOC control technology would be commercially available in one year.

Possibilities do exist to facilitate an expedited roll out of PM and VOC abatement technology. Equipment is already available for shuttle tankers to recycle VOCs from cargo, which could potentially be adapted for emissions abatement. There are also combinations of exhaust gas cleaning technologies that can be adapted, such as selective catalytic reduction (SCR) equipment for removing NOx from engine exhaust gases.

When asked ‘Do you think a combined scrubber and SCR unit is a mature EGCS configuration?’ 60% of the audience said yes, another 20% said no and 20% were not sure.

Mr Gregory called on IMO to work faster in introducing legislation, such as Marpol Annex VI regulations, on cutting marine air pollution further.

However, 50% of the webinar audience thought Marpol Annex VI regulations were effectively cutting air emissions toxicity.

You can view the webinar, in full, in our webinar library.

And you can sign up to attend upcoming webinars on our events page.