Hundreds of people fell sick following a gas leak at a chemical plant. This gas leak reminds everyone of one of the worst industrial disasters in Bhopal. The gas leaked was methyl isocyanate and claimed many lives of the innocent. Now, styrene is the suspected gas leaked at LG polymers.
The gas exposure not only attacked people who were passing the street, but it also claimed the lives of innocent animals. Styrene is highly toxic and cannot spread over 4-5 km. It is liquid and has a high boiling point. It wouldn’t leak until a fire or explosion increased the temperature causing a gas leak.
What is styrene?
Styrene (vinyl benzene) is an essential industrial chemical used in the synthesis and manufacture of polystyrene and different copolymers. It is a flammable liquid used in the production of polystyrene plastic, fiberglass, rubber, and latex. And also found in vehicle exhaust, cigarette smoke, and in natural foods like fruits and vegetables.
Composition: Styrene, also known as ethenyl benzene, vinyl benzene, and phenyl ethane, is a benzene derivate. It is the primary raw material for the plastic industries. The conventional method of producing styrene involves alkylation of benzene with ethylene to generate ethylbenzene, followed by dehydrogenation of ethylbenzene to styrene.
Signs and symptoms of Styrene exposure
Styrene is moderately toxic but may give severe injuries by inhalation and ingestion.and long term exposure is fatal. Work-related exposure involves inhalation and skin contact. The International Agency for Research on Cancer classifies styrene as a possible carcinogen. Anyone with exposure must attend to immediate medical care.
Symptoms of short-term exposure
- Respiratory complication
- Irritation in the eye and mucous membrane
- Gastro-intestinal issue
- Bleeding and bruising
- Tiredness and night sweats
Symptoms of long-term exposure
- Exposure attacks the central nervous system leading to frequent headaches, hearing loss, and fatigue.
- Can result in peripheral neuropathy
- Cancer and depression in some cases
- It can also result in an abnormal heart rate.
- Exposure increases the risk of leukemia and lymphoma.
- Can also result in loss of consciousness and death with long-time exposure
Respiratory complications due to exposure
Styrene is known to result in non-malignant respiratory disease among workers. Asthma and obliterative bronchiolitis are the most frequently reported cases among the workers associated with styrene.
Obliterative bronchiolitis (OB)
It is a rare and irreversible condition associated with toxin inhalation. The onset of cough and airway obstruction is the typical characteristic symptoms of OB. The risk of developing OB after styrene exposure increases. The effects occur between a couple of weeks to months at the beginning of employment. The condition usually stabilizes after the exposure ends. There is no appropriate medical diagnostic code for OB.
The contrary conclusions increase the possibility of OB deaths, which were wrongfully classified as COPD (Chronic obstructive pulmonary disease). Workers associated with styrene exposure leave the workforce early. Conclusively, exposure to styrene increases the risk of developing respiratory complications, leading to a sudden or prolonged death.
Asthma
Additionally, authorities also classified styrene as a possible asthma-causing agent. Workers frequently faced inhalation challenges. Their condition developed after changing jobs or eliminating exposure to styrene. Exposure results in a higher prevalence of wheezing and tightness and airway obstruction. Moreover, smoking increases the risk.
What happens soon after styrene inhalation?
After styrene inhalation, the body rapidly absorbs it. Mandelic acid and phenyl glyoxylic acid are the primary metabolites of styrene. About 85% of absorbed dose metabolizes into mandelic acid and 10% phenyl glyoxylic acid. The system finally excretes the products via urine. This deposition is soon after the end of the exposure.
Occupational safety and health administration (OSHA) permissible exposure limit is over 8-hour time-weight average (TWA) is 100ppm. And the national institute for occupational safety and health (NIOSH) gives a recommended exposure of 50ppm. However, the short term exposure limit is 15 minutes.
Medical test to determine the exposure of styrene
The following test may be used to test the individual and can mention especially workers in the industrial field.
Urinary mandelic acid
In urine analysis, the standard concentration of Mandelic acid should be 297mmol/mol creatinine (2.6mol/L). Doctors recommend urine analysis of the worker’s at the end of their shift. Others who do show some symptoms should get tested before they start exhibiting the abnormalities.
Other compounds like ethylbenzene, after metabolism, can also be excreted as mandelic acid in urine. This metabolism gives negative results for the mandelic acid concentration. Alcohol consumption inhibits the excretion of mandelic acid. Thus, the anticipated results should be three times lower than the standard levels. It is vital to note the units of alcohol the specific subjects consume.
Urinary styrene concentration
Urinary styrene concentration can also serve as a measure of styrene exposure. Moreover, it is the most appropriate diagnosis comparatively. Besides, the time of collection plays a vital role in this diagnosis.
The liver function test serves as another method of diagnosis. Although, the lack of specificity makes the interpretation of the result difficult.
Effect of the gas on animals
Animal studies show that inhalation of styrene can result in damage to the lining of the nose and damage to the liver. Moreover, they are more susceptible than men. Thus, the effect is more substantial, resulting in liver damage and respiratory complications, eventually leading to immediate death.
