Air pollution found to increase emergency room admissions for bleeding peptic ulcers

Air pollution is seen as one of the leading causes of respiratory diseases. However, researchers from the University of Hong Kong have identified another organ group it affects – the digestive system. According to their study, which is published in the journal Lancet Planetary Health, exposure to elevated levels of nitric oxide (NO₂) could trigger bleeding among patients with peptic ulcer, and increase the likelihood of emergency admissions. The research team used a case-crossover study in the city’s elderly population to determine the effects of differing levels of exposure in their health, particularly their gastrointestinal systems.

A peptic ulcer is defined as “a break in superficial epithelial cells of the gastroduodenal mucosa.” This is typically followed by pain, bleeding, or even perforation (or puncturing) of the affected region. Bleeding is a typical complication of peptic ulcer, and it requires prompt medical assistance and admission. In hospitals around Hong Kong, the incidence of people being brought in because of bleeding related to peptic ulcer accounted for 40 percent of all cases in 2010. While this has gone down in recent years, the condition remains to be a condition that can cause mortality. It is also a condition that burdens people economically and diminishes the quality of life overall. (Related: We know air pollution contributes to disease; now a new study finds air toxicity also causes psychological stress.)

One of the risk factors for peptic ulcer bleeding are infections caused by the Helicobacter pylori bacteria, the use of non-steroidal anti-inflammatory drugs (NSAIDs), as well as low dosages of blood thinners such as aspirin. Still, this increase in cases of bleeding cannot be fully explained by these instances alone, according to the researchers. Thus, they have posited that there may be other factors at work, in particular, the environment. Earlier studies have also pointed out an increase in cases of bleeding during specific seasons. The researchers in their current study considered all this.

The study gathered daily air pollution data from the Environmental Protection Department. The data covers all particulate matters that have an aerodynamic diameter of 2.5 micrometers or less, such as nitric oxide (NO₂), sulfur dioxide (SO₂), and ozone (O₃). The data used spanned from 2005 to 2010. Also, data regarding cases of emergency admission due to peptic ulcer bleeding was collected from the Hospital Authority of Hong Kong. The sampled data were from older adults aged 65 years and above, and it also covered the same time frame used in the pollution data.

Both sets of data were cross-referenced to measure which particulate was present at the time where there were the most cases of emergency admissions due to peptic ulcer. The team assessed both single pollutant and multi-pollutant levels, with cardiorespiratory diseases being positive controls.

Results indicated that there were 8,566 emergency admissions for peptic ulcer bleeding among Hong Kong’s elderly population from 2005 to 2010. Where there is an increase of NO₂ concentration in the air, it resulted in a 7.6 percent rise in emergency admission for bleeding due to peptic ulcer. Other pollutants such as SO₂ and O₃ were not linked to the increase of cases.

While researchers stated that the relationship between air pollution and its effect on peptic ulcer is still unclear, they posited that exposure of the gastrointestinal tract to toxins in the air through the mucociliary clearance, as well as cases wherein they consume it through contaminated foods, could account for the rise in peptic ulcers. The NO₂ swallowed through these processes might cause oxidative damage or inflammation and increase the likelihood of bleeding.

“These findings strengthen the hypothesis that air pollution affects not just cardiopulmonary diseases, but also certain diseases of the digestive system,” the researchers concluded. “Future patient-level and mechanistic studies should be done to substantiate the findings.”

Learn more about how air pollution damages our body by going to Pollution.news today.

Sources include:

Science.news

TheLancet.com