Riverton Fire Aftermath: The Impacts of Benzene on Public Health

There is still considerable concern over the long-term health impact of the recent fire at Riverton city dump, which emitted smoke and pollution for over two weeks into the largest built-up area in Jamaica – Kingston, St. Andrew and St. Catherine. The Jamaica Environment Trust (JET) just shared this article on a chemical of particular concern – but there are many other pollutants in the air we have been breathing.

…And there is no "Planet B." — …And there is no “Planet B.”

What is air? We cannot live for even a minute or two without it. What is more important? The air that keeps us alive (or poisons us, as the case may be) or whether the politically-appointed head government officials appointed should leave or stay? We must keep focused on the terrible damage done to our environment and public health. And plan for it never to happen again. I hope you find this article useful.

The impacts of Benzene on Public Health
By Dr. Homero Silva
Professor in Public Health, Environment and Climate Change
School of Public Health and Health Technology
University of Technology
March 31, 2015

The Ministry of Health’s acknowledgment of the highest benzene concentration ever recorded in Jamaica’s air following the March 2015 fire at the Riverton dumpsite is only the tip of the iceberg. The weak air quality monitoring programme conducted by the National Environment & Planning Agency (NEPA) prevents the public from appreciating the real magnitude of Jamaica’s environmental health problems, especially those related to poor solid waste management. Air pollutants such as some of those from the “Dirty Dozen” (Dioxins, Furans and PCBs), Biphenol A and heavy metals are not measured, but they are more dangerous to health because they can be accumulate in the body, especially in fatty and soft tissues. Metals differ from other toxic substances in that they are neither created nor destroyed by humans. These pollutants will be dealt with in another article. This time I will focus on benzene.

Background monitoring stations report concentrations of benzene from sources other than dump fires, such as motor vehicle emissions, so the high concentration event cannot be separated from the year-round low, but risky benzene concentrations. The World Health Organization (WHO) considers that Benzene is carcinogenic to humans and no safe level of exposure can be recommended. Using WHO estimates of the excess lifetime risk of leukaemia at an air concentration of 84 µg/m3, the estimate is 494 cases per million population.

Ontario regulations propose a 24-hour average standard of 2.3 μg/m3 for Benzene, based on the carcinogenic effects associated with exposure to Benzene. The concentration of benzene at the Half Way Tree Road background monitoring station was 7.87. Two weeks after the 2012 fire, the benzene concentration was 13. Therefore, background benzene concentrations in Jamaica EXCEED the Ontario standard. Jamaica does not have standards for benzene.

The risk of harmful health effects from toxic substances depends on many factors, such as: dose, health, age, adaptation, routes of exposure, frequency and duration of exposure (acute vs. chronic).

Benzene is a carcinogen (causes cancer), mutagen (causes mutations in DNA), teratogen (causes birth defect), allergen (causes unnecessary immune response), neurotoxic (damages nervous system) and endocrine disruptor (interferes with hormones).

High concentrations of benzene cause the following short term effects: drowsiness, dizziness, rapid or irregular heartbeat, headache, tremors and confusion immediately after exposure to high levels of the substance.

Long term exposure to benzene causes other health problems like: aplastic anemia; excessive bleeding; reduction in the capacity of the immune system to fight infections, cancers; and chromosomal aberrations in human peripheral lymphocytes.

Other studies have also found that:

· Benzene crosses the placenta and is present in cord blood in concentrations equal to or greater than maternal blood.

· Women exposed to benzene concentrations of 2.86 to 7.44 µg/m3 had a 2.3 odd ratio of having child with neural tube defect (spina bifida) and a 1.28 odd ratio for having a child with anencephaly (improper formation of the top part of the skull and brain).

· Early-life exposure to ambient air pollution may increase the risk of upper and lower respiratory tract infections in infants.

· Increase in preterm birth or a decrease in biparietal diameter growth with maternal exposure to benzene or early exposure to aromatic solvents. Biparietal diameter (BPD) is one of the basic biometric parameters used to assess fetal size. BPD together with head circumference (HC)

· Benzene is fetotoxic (causes mutations in DNA) in mice and rabbits following maternal exposure by inhalation, causing a reduction in birth weight.

· Results of animal studies showed that benzene may cause Zymbal-gland (ear canal) carcinoma, oral-cavity tumors, skin cancer, lymphoma, lung tumors, ovarian tumors, and mammary-gland carcinoma.