A Putative Adverse Outcome Pathway Relevant to Carcinogenicity Induced by Sulfuric Acid in Strong Inorganic Acid Mists

Abstract

Based on epidemiological studies, an International Agency for Research on Cancer Working Group determined that strong inorganic acid mists containing sulfuric acid are carcinogenic to human even though, sulfuric acid, per se, is not. Accumulative studies indicate that there is a link between chronic occupational exposure to sulfuric acid mists and an increased risk of laryngeal cancer. Unintended, acute exposure to sulfuric acid mists can cause corrosive damage to target tissues depending on the route of exposure. This review compares the toxicity and carcinogenicity of sulfuric acid mists compared to other strong inorganic acid mists. It also examines the routes and duration of exposure (short-term, prolonged, and long-term). In vivo evidence does not support or refute the carcinogenicity of sulfuric inorganic mists even though its co-carcinogenic or promoting potential has been considered. On the basis of existing evidence on sulfuric acid mist toxicity, we suggested a putative adverse outcome pathway (AOP) relevant to carcinogenicity caused by mists containing sulfuric acid. A possible key factor involved in sulfuric acid mist carcinogenesis is the genotoxic effects of low pH since it can increase instability in chromosomes and DNA. A putative AOP for sulfuric acid mist carcinogenicity would help generate better risk assessments and more accurate predictions regarding the risk of developing cancer due to prolonged exposure. Establishing an AOP would also be useful for future studies examining the carcinogenicity of other strong inorganic mists.

Application of Standardized Proportional Mortality Ratio to the Assessment of Health Risk in Relatively Healthy Populations: Using a Study of Cancer Risk in Telecommunication Workers with Excess Exposure to Acid Mists as an Example

“…Although some evidence showed that gastroesophageal reflux was an important risk factor of stomach cancer [23], it is unclear whether inhalation and subsequent ingestion of acid mists can cause similar effects. Since low pH can increase instability in chromosomes and DNA, it has been proposed that acid mists cause cancers through genotoxic effects [24].…”

Atmospheric Dispersion of Gaseous Amine Emitted from Absorption-Based Carbon Capture Plants in Saskatchewan, Canada

“…The byproduct, sulfuric acid (H 2 SO 3 ), is an extremely hazardous substance, which causes stinging, burning, and eye irritation. A deep breath of sulfuric acid vapor, even in small amounts, can cause coughing and a risk of laryngeal cancer depending on the human sensitive group, time, and concentration to which they were exposed [12,38,39]. Another byproduct, nitric Acid (HNO 3 ), is an extremely hazardous gas, which has effects on the lungs caused by inhalation of a wide range of gases.…”

Evidence of Sulfuric-acid Emitted from the Underground Coal-fire at Wuda of the Inner Mongolia of North China

“…As a result, sulfuric acid was one of the most important factors that to haze and smog events (Li et al, 2011). It had been reported that PM 2.5 for every 1µg/m increase in concentration, the mortality rate of urban population would increase by 25 per million people (Yang et al, 2019), and that the concentration levels of PM 10 were strongly related to children's hospitalization for asthma and tracheitis (Perez-Diaz et al, 2017). Sulfuric acid was also one of the culprits for acid rain (Li et al, 2021a).…”