The Devastating Impact of Scrubbers on Ocean Pollution
Recent studies have revealed the colossal damage that scrubbers are inflicting on the world’s oceans, over 42 months since the global sulfur cap became law. Research from Chalmers University of Technology in Sweden demonstrates that water discharged from scrubbers accounts for over 90% of contaminants found in water samples.
Urgent Need for Stricter Regulations
Anna Lunde Hermansson, a doctoral student at the Department of Mechanics and Maritime Sciences at Chalmers, emphasizes the need for more stringent regulation to reduce the deterioration of the marine environment. Traditional environmental risk assessments of emissions from shipping tend to focus on one source at a time, and while all industries have multiple sources of emissions, the cumulative environmental risk in ports must be considered.
Shipping’s Multiple Sources of Emissions
Ships are responsible for various types of emissions, including greywater, blackwater, antifouling paint, and scrubber discharge water. The Chalmers study looked at emissions from a cumulative perspective, focusing on scrubber water’s contaminants such as heavy metals and toxic organic compounds. Open-loop scrubbers, which account for the majority of kits sold worldwide, pump contaminated scrubber water directly into the sea without a cleaning step in between.
An Underestimated Environmental Threat?
Lunde Hermansson points out that although new guidelines for environmental risk assessments are in progress, assessing one source of emissions at a time results in an inadequate overall assessment. The researchers studied four different port environments to determine contaminant concentrations from five different sources, using actual data from Copenhagen and Gdynia for two of them. These ports were chosen due to high shipping traffic volumes and a significant proportion of ships equipped with scrubbers.
Alarming Cumulative Risk Levels
The results revealed cumulative risk levels five and thirteen times higher than the acceptable risk limit in the studied ports. More than 90% of environmentally hazardous metals and PAHs in the samples came from scrubber discharge water, while antifouling paints were responsible for the largest copper and zinc load. The only port environment with an acceptable risk level in the researchers’ study was one with the highest water exchange per tidal period.
A Worldwide Effort to Combat Scrubber Water Discharge
Recognizing the environmental threat, several countries have instituted scrubber water discharge bans. The Swedish Agency for Marine and Water Management and the Swedish Transport Agency has submitted a proposal to the Swedish government to prohibit scrubber water discharge in internal waters. According to Clarksons Research, more than 5,000 ships, or approximately 5% of the global merchant fleet, are now equipped with scrubbers – an alarming figure.
Has the Global Sulphur Cap Improved Atmospheric Conditions?
Despite the prevalent criticism of acidic scrubber discharges, studies from NASA in October 2020 suggested that implementing the global sulfur cap has led to improvements in atmospheric conditions. Ship track clouds dropped dramatically in 2020, following the first year of fuel regulation implementation, which reduced sulfur content from 3.5% to 0.5% for most of the global fleet.
While there may be potential benefits to implementing the global sulfur cap, it is undeniable that more stringent regulations are needed to address the massive damage to our oceans caused by scrubber discharges. It is crucial that both the shipping industry and governments work together to ensure a sustainable future for our marine environments.
