Stomach cancer - Ethylene oxide exposure claim

Research linking EtO exposure to stomach cancer

When ingested or inhaled, EtO can cause damage to DNA as well as genetic mutations. Both can further lead to cancer.

Aside from blood cancers such as lymphoma and leukemia, multiple studies also suggest a connection between EtO exposure and stomach cancer. These include a 1986 study examining its health effects on 733 exposed industrial workers. Of this number, researchers found that six had stomach cancer.

Likewise, a meta-analysis of 10 different cohort studies found evidence suggesting an association between exposure to EtO and certain types of cancers. It includes stomach cancer.

Due to its harmful effects on human health, both the International Agency for Research on Cancer (IARC) and the Environmental Protection Agency (EPA) tagged EtO as a human carcinogen. Stringent regulations have been put in place to minimize exposure to the toxic chemical, both in workplaces and communities.

OSHA’s Permissible Exposure Limits (PELs) for EtO are a 1 ppm (parts per million) limit for an 8-hour time-weighted average (TWA). For short-term excursions, individuals should not be exposed to EtO beyond the 5 ppm limit.

Stomach cancer: Symptoms and risk factors

Stomach cancer occurs due to abnormal cell growth in the stomach. Here in the United States, roughly 30,000 individuals are diagnosed with stomach cancer each year. The following are common symptoms associated with stomach cancer, according to the National Cancer Institute.

• heartburn
• stomach discomfort
• indigestion
• feeling bloated, especially after eating
• mild nausea
• appetite loss
• blood in the stool
• vomiting
• unexplained weight loss
• stomach pain
• jaundice
• ascites or buildup of fluid in the abdomen
• difficulty in swallowing

The exact causes of stomach cancer remain unknown. However, known risk factors can increase its likelihood. These include H.pylori infection, which causes peptic ulcers. Genetics, lifestyle choices, and environmental and occupational exposure to toxic substances can also contribute to increased risks of stomach cancer.

How ethylene oxide is causing stomach cancer

Ethylene oxide, when absorbed through inhalation or ingestion and distributed via the bloodstream to the gastric epithelial cells, can cause malignant tumor formation.

Ethylene oxide (EtO) is a mutagenic and genotoxic chemical that can damage the DNA of gastric cells, leading to genetic mutations, tumor formation, and growth. The primary way EtO, known as a direct alkylating agent, causes cancer is by forming bonds with molecules. The formation of DNA adducts modifies DNA structure, and insufficient repair of these adducts results in genetic mutations and chromosomal aberrations that affect proto-oncogenes and tumor suppressor genes essential for regulating cell growth. 

The loss of normal cell-cycle control results in uncontrolled cell growth, and the proliferation of mutated cells can ultimately lead to the formation of tumors in the gastric tissue. Laboratory studies on animals show that direct exposure to EtO produced tumors in rodents' forestomach, proving that high local ethylene oxide doses to the stomach lining tissue can lead to cancer development.