For their research, Hinz and her colleagues enlisted the help of New Zealand customs. Employees used probes that they pushed through the rubber gaskets of the container doors to collect gas samples from 490 sealed containers. Hinz also collects air samples from dozens of other containers herself, monitoring how the concentrations of compounds change in real time as the bin is opened and the air inside is allowed to mix with the air. fresh air outside.
The investigation revealed a lot of nasty substances. Customs officers found methyl bromide, the compound that overwhelmed shipbuilders in Rotterdam, in 3.5% of sealed containers. They found formaldehyde in 81% of the containers, and ethylene oxide in 4.7%, to name a few. Exposure to ethylene oxide can cause various unpleasant symptoms, including nausea, vomiting, and diarrhea. Formaldehyde, a preservative, is a carcinogen and can also cause internal irritation when inhaled, among other symptoms.
In their study, Hinz and her colleagues found that some measured concentrations appear to be high enough to trigger an acute reaction that causes immediate symptoms. However, Hinz said that, in practice, it is unusual for a worker to be directly exposed to such high levels of toxic gas. Instead, there is a more common but still notable risk of repeated exposure to low concentrations. For example, long-term exposure to these chemicals can increase the risk of cancer or cause mental problems. However, very little research exists on the risks of chemicals inside cargo containers.
“I definitely think it needs attention, much more attention than it needs to,” Hinz said.
Gunnar Johanson, a toxicologist at the Karolinska Institutet, Sweden who acted as a reviewer for Hinz’s study, agrees with her assessment.
“We don’t know exactly how big the risk is, but it’s an unnecessary risk, because you can easily deal with it,” he said. All it takes is better ventilation.
A few years ago, Johanson and his colleagues were called in to inspect a suspicious container in Sweden. It was filled with rice, but inside was also a strange blue bag filled with white powder. When Johanson analyzed the air, he found phosphine, a disinfectant, at a level of concentration high enough to cause death.
To protect the shipbuilders, Johanson and his colleagues designed a device that connects to the exhaust fan and attaches to the ventilation holes – but very small – found on the face of most containers. Experiments show that once the device is turned on, the concentration of harmful gases drops within minutes.
“We can reduce the amount of pollutant evaporating by about 90 percent in an hour,” says Johanson. He added that this vehicle is currently being used by Swedish customs authorities.
Martin Cobbald, chief executive of Dealey Environmental, an environmental services company in the UK, there is a need for greater awareness in the transport and logistics industry about the dangers associated with exposure to toxic gases in shipping containers.
His company regularly contracts to open and ventilate the containers, but he adds, “We don’t do it nearly as much and for as many people as we should.”
