“We lived in a house about 20 yards away from an oil well. Another Texaco oil well was upstream from where we got our drinking water, and the water was usually oily with a yellowish foam. I had 11 children. I lost Pedro when he was 19. He had three cancerous tumors: in his lungs, liver, and his leg.” – Woman from town of Sacha, Orellana, Ecuador.
“It started with a little sore on my toe, which grew a bit larger. The water near my house, where I washed clothes, was full of crude and the sore grew bigger, as if the flesh were rotting.
It didn’t hurt, but I couldn’t stand its stink. I had a fever and chills.” – Woman whose leg was surgically excised due to cancer.
“The girl is 15, she’s very sick. She was born that way, not moving with soft bones. The doctors were never able to tell me what was wrong with her. Now she can sit up, crawl, pull herself along the floor, turn over.
She says “mama”, “papa”, and cries when she’s hungry or thirsty….I have to feed her by hand.” – Mother whose daughter has birth defects.
In a nutshell, oil spills may occur all around us, have potential to contaminate soils, sediment and water (both surface and groundwaters) and air. Subsequently, spill oils have significant negative impacts on the residents of the affected areas either by direct or indirect way depending on the type of contact with the oil spill. Prevailing weather conditions will play key role in influencing the physical characteristics and behavior of spilled oil at the site.
Mental health in cleanup workers and residents who exposed to oil is significantly affected. Studies conducted after massive oil spills (such as Exxon Valdez accident, Sea Express and Prestige spills) revealed that there is high prevalence of anxiety disorder, depression, posttraumatic stress disorder, psychological stress in oil-exposed population. Individuals living closer to the spill sites showed increased frequency of psychopathological symptoms like anxiety, hostility, and somatization, with lower perception of physical health and functional capacity (Palinkas et al., 1993).
After the Prestige oil spill, though there were no general effects in the preschool children, but primary school aged children showed higher hostility to others after oil spill, suggesting that the ‘problem of social adjustment’ was clearly appearing in the oil-exposed individuals (Perez-Pereira et al., 2012). The academic scores in adolescent group were dramatically dropped after Prestige oil spill. Higher risks of stress and depression, but no signs of suicidal impulse were observed in the residents exposed to Hebei Sprit spill.
However, the scenarios were different in a larger group of residents of coastal communities at Hebei Spirit spill, where people showed wide array of mental disorders including anxiety, depression, posttraumatic stress disorder, suicidal thoughts, which is attributed to their exposure level and/or proximity to the spill site. It has also been found that mental health effects, especially anxiety and depression were higher in residents living closer to heavy and moderately oil-soaked areas than in residents from lightly oil-soaked areas.
Also, increased levels of depression have been observed in children living closest distance to contaminated coastline compared to children living farthest distance. In order to know the impact of pollution effect on mental health in human, a factor or scale has been introduced called ‘burden of disease’ (BOD) (Kim et al., 2013b), which helps to measure the health damage and useful for the assessment of compensation cost. Data analysis in contaminated sites revels that BOD remains for 1 year for the people exposed to oil and residing near contaminated coastal areas.
However, BOD is known to be affected by several parameters, such as proximity to the spill site, participation in the cleanup activities, posttraumatic stress disorder, asthma etc. After Deepwater Horizon oil spill also, oil-exposed individuals were found to show increased symptoms of anxiety, depression, and posttraumatic stress. Especially, the risk was higher in individuals with low income, low social support, and high levels of nonorganizational religiosity. In Gulf Coast, more than one-third children exposed to oil experienced either mental health distress or physical symptoms.
Economic problems are the additional contributors to the mental health disorders in oil exposed individuals. Worse scores of anxieties, confusion, depression, fatigue, total mood disturbance scales, less resilience were observed in people with spill-related income loss than those with stable income. A questionnaire was conducted in the Gulf Coast area after an oil spill, which revealed that though emotional and psychological symptoms were declining and more individuals were started to work, families were still experiencing severe chronic stressors and disruption. Such metal disorders in the family is attributed to job loss and changes in the economic conditions. Thus, there is abundant evidence to establish the relationship between oil spills and mental health effects in exposed individuals.
About the respiratory tract, gasoline can irritate the mucous membranes. But in the case of severe exposures, extensive damage in respiratory tract is possible by gasoline, such as acute exudative tracheobronchitis, edema, intrapulmonary hemorrhage, pulmonary congestion etc. Pneumonitis is possible from the pulmonary aspiration of ingested gasoline. The vapors of petroleum hydrocarbons (e.g. gasoline) can sensitize the myocardium to circulating epinephrine, which may result in the potentially fatal ventricular fibrillation.
There is a high possibility for fatty degeneration of the proximal convoluted tubules and glomeruli, and renal failure if massive amounts of petroleum hydrocarbons are inhaled. Persistent respiratory symptoms with elevated of airway injury in breath condensate has been found in cleanup workers 2 years after Prestige oil spill. But even after 5 years also, Prestige oil spill affected individuals were found to show increased risk of lower-respiratory-track symptoms including cough, phlegm, shortness of breath, wheeze etc., which suggest that the respiratory symptoms may persist up to several years (~ 5 y) after exposure. In individuals exposed to the Tasman Spirit oil spill have suffered higher rate of health effects such as cough, eye irritation/redness, general illness, head-ache, nausea, runny nose, sore throat etc. But effects were even worse in persons exposed to oil for 15 days at the Tasman Spirit oil spill site, mainly there was lung dysfunctions with significant reductions in the spirometry parameters.
On the other hand, several volatile organic compounds (VOCs) such as benzene, ethylbenzene, xylene, and PAHs are known to induce respiratory tract irritation, bronchitis and irritation to skin. Especially, PAHs with 3 to 5 benzene rings have potential to induce oxidative stress in the respiratory tract and aggravate asthma symptoms. Multiple diagnostic and clinical tests (e.g. skin prick test, methacholine bronchial provocation test, pulmonary function test) have confirmed that the children exposed to crude oil spill will increase the risk of asthma. VOCs, especially aromatic compounds are associated with adverse respiratory effects like asthma in adults. Nevertheless, respiratory hospitalizations, nocturnal cough, pleural mesothelioma, obstructive lung disease etc., are very common effects in individuals exposed to oil spill. In one study, transcriptomics has been used to reveal the potential effects of oil and oil dispersants on the respiratory system at molecular level. Human airway epithelial cells were grown by exposing them to crude oil, dispersants (Corexit 9500 and Corexit 9527), and oil-dispersant mixtures (Liu et al., 2016). Corexit 9500 had shown drastic changes in the expression of ~ 84 response genes.
According to gene ontology functional term and pathway-based analysis, gene sets related to angiogenesis and immune responses were upregulated, and gene sets involved in cell junctions and steroid synthesis were downregulated. Such effects were observed in cells treated with Corexit 9500, oil or Corexit 9500 + oil mixture. Nevertheless, key molecular signatures identified in this study have been well coincide with pathological features observed in common lung diseases, including asthma, cystic fibrosis, and chronic obstructive pulmonary diseases, which suggest that crude oil and dispersants have an immense effect on respiratory system. Sometimes, as a part of cleanup procedures, spilled sites are treated by “in situ burning” of trapped oil on the surface of water columns. However, this generates potentially toxic substance called oil sail particulate matter (OSPM) (Jaligama et al., 2015). In experimental mouse, OSPM caused cytotoxicity in a dose- and time-dependent manner, concurrently results in the generation of reactive oxygen species, and superoxide radicles. OSMP exposed mice have shown decreased body weight gain, systemic oxidative stress, airway inflammation.
Additionally, OSPM was found to be as a key element in increasing the number of T helper 2 cells (Th2), peribronchiolar inflammation, increased airway mucus production in a mouse model of allergic asthma. These findings clearly demonstrate that OSPM has potential to cause pulmonary inflammation and alters the innate/adaptive immune responses in experimental animals and suggest the threat to respiratory system from cleaning up an oil spill by “in situ burning”. In sub-Saharan Africa, ambient air pollutants have been assessed for their toxicity effects on respiratory system in schoolchildren living in a city (Durban, South Africa) where there is intense activities concerning importation of crude oil and exportation of petroleum and petroleum products (Mentz et al., 2018). As anticipated, increased occurrence of respiratory symptoms among the schoolchildren were identified, with the evidence of chest tightness, cough, shortness of breath etc.
Hematologic system in human is also known to be affected by TPHs. Incidences of nonlymphocytic leukemia, acute lymphocytic leukemia, chronic myelocytic leukemia, and chronic lymphocytic leukemia are higher in individuals exposed to oil than unexposed individuals. In DWH oil spill victims, decreased blood parameters have been observed, such as white blood cells and platelet counts, blood urea nitrogen, creatinine, hemoglobin, hematocrit, and urinary phenol levels (D’Andrea and Reddy, 2014). In contrast, mean hemoglobin and hematocrit levels were significantly increased in people exposed to oil compared with the unexposed individuals.
Furthermore, in spill affected individuals, high levels of serum liver enzymes such as alkaline phosphatase, aspartate amino transferase, and alanine amino transferase were observed. After Prestige oil spill, elevated levels of two heavy metals (e.g. aluminum and nickel) were detected in the blood samples of exposed humans. Incidences of childhood leukemias were positively correlated with in the children living closer to oilfields in Ecuadorian Amazon (Hurtig and San Sebastian, 2004). Ninety-one cancer cases have been recognized in age group of 0-14 years, with significantly elevated levels in the youngest age group of 0-4 years, with a relative risk of leukemia ranging from 2.56 to 3.48. The most toxicological VOCs of petroleum hydrocarbons e.g. benzene, toluene, xylene and PAHs.
In these, benzene is a well-known cause of leukemia and other hematologic neoplasms. Nevertheless, studies conducted in US and China also revealed that there are high incidences of leukemia cases in oil-field workers (Yang and Zhang, 1991; Sathiakumar et al., 1995). The incidences of several kinds of leukemia (e.g. acute nonlymphocytic leukemia, acute lymphocytic leukemia, chronic myelocytic leukemia, chronic lymphocytic leukemia etc.) were significantly were higher in people living in oil fields and polluted areas that those in other areas (Yang and Zhang, 1991).
In the renal system, many disorders are caused by the ingestion of gasoline, including elevated levels of serum creatinine, urinary protein, glucose, hemoglobin, and BUN. The other frequently observed symptoms are oliguria, tubular necrosis, interstitial edema, hematuria, and reduced creatinine clearance. In general, acute renal toxicity resolves with treatment. Ingestion of petroleum hydrocarbons causes severe damage to the digestive tract such as esophagitis, gastritis, disruption of epithelium and mucositis of the oral cavity.
Vapors of petroleum hydrocarbons such as gasoline can cause skin inflammation. Irritant contact dermatitis, degreasing, burns, redness and blisters are common during prolonged contact with liquid petroleum hydrocarbons. Vapors of petrocarbons induce eye irritation, which starts from a concentration of 200 ppm. Burning pain and transient corneal injury are possible when petroleum hydrocarbons splashed in the eyes. But chronic exposure to these compounds leads to sever damage to cornea, retina, and ciliary body.