The biggest ever oil spill accident in Korea, the Hebei Spirit oil spill, happened in the sea near the west coastline of the Korean peninsula on December 7, 2007. The amount of spilled oil was more than 12,547 kL, and reached the western coastline with a spread of 1,052 km. Taean-gun, the most severely damaged region, is a densely populated coastal area where people have been heavily dependent on maritime activities.

Oil spills pose a complex mixture of chemical hazards which can be absorbed by the human body through diverse media including air, water, and seafood, and via multiple routes such as inhalation, ingestion, and skin contact. Furthermore, oil spill disasters induce socioeconomic disturbances, including enormous amounts of economic damage as well as a disruption to community bonds. Economic problems induced by oil spill accidents have caused psychological distress in communities [1]. Within one year after the Hebei Spirit oil spill, four local residents committed suicide, which shows that their sense of loss was multifaceted and deep-seated.

Studies on the Hebei Spirit oil spill accident have reported a general sense of stress and depression among a number of people in the affected area [2]. However, investigations on children in that area have not been conducted. We aimed to examine the mental health effects of the oil spill on children living in the affected area, where most of their families were victims of the accident.

About 84% of children in the study responded to the survey questionnaire. More than 75% of the information on their father's educational level was missing because the supervising teachers in participating schools did not want to include the question in the questionnaire. Children who showed a higher prevalence of depression and anxiety symptoms were more likely to be female, older, and concerned about the impact of the oil spill exposure on health (Table 1).

The risk of depressive symptoms was significantly higher in children whose schools were closest to the nearest contaminated coastline compared to those farthest away; the odds ratio was 2.20 (95% confidence interval=1.29-3.74). The risk of depression symptoms increased significantly according to a decrease in distance from the nearest contaminated coastline to the children's attending school, with a dose-dependent response (p-trend=0.004), while there was no significant association between depressive symptoms and distance to the residence. Although the risk of anxiety symptoms showed an increase according to a decrease in distance to the school or residence, there was no statistical significance (Table 2).

We found that the risk of depressive symptoms in children increased in areas that were contaminated by a high degree of oil spill, as measured by the distance from the contaminated coastline to their attending school as a surrogate, even after adjustment for potential confounders and covariates.

The prevalence level of depression in this area (10.3%) was much higher than in a Korean rural area (1.6%), but similar to the level in a noisy community where an air force base was located (11.7%) [5]. However, it is hard to disentangle the direct effect of exposure to the chemico-physical agents of hazardous crude oil on mental health and psychological consequences through the socio-economical damage by the oil spill accident.

Early life is a period of unique sensitivity with long lasting effects on mental health [6]. This study is the first to examine children's mental health in the area affected by an oil spill disaster. The initial heavy exposure to volatile organic compounds from the spilled crude oil may have neurological effects [7], including effects on affection and moods. However, the perceived threat rather than the disaster agent itself is deemed to be more important in children's post-disaster psychopathology [8]. Even though the oil spill accident itself did not accompany life-threatening features, its consequences due to socio-economic disruptions may have impacts on the mental and physical health of children.

Disasters may increase the risk of psychopathology in children because they may disrupt family functioning through causing psychopathology in the parents or disrupting the social network of the parents [9]. Incidents of adult suicide in the community immediately after the oil spill accident, as well as serious social conflicts aroused by the endless delay to compensation and parents' or caregivers' desperation, may increase the risk of depression and anxiety in children.

This study has limitations that need to be considered. As mentioned in the results section, we could not obtain information about the family's socio-economic status in 75% of the study population, which was initially planned to be acquired by the question about the father's educational level. In Korea, the parental educational level has been reported as a good variable to reflect familial socioeconomic position (SEP) in children [10]. Vulnerability and capacity to recover from disaster are usually dependent on the victim's SEP. Another limitation was that the study subjects did not include younger children below the 3rd grade of elementary school because we only included children who were considered capable of responding to the questionnaire by themselves. However, a previous review on children's mental health and disasters reported that it is important to ask children directly about their responses to disasters, regardless of disaster type, rather than relying on caregivers' assessments [11].

Children's mental health in the area affected by the Hebei Spirit oil spill accident was associated with the degree of the accident impact. A mental health program in the community should include children as well as their parents and family as victims of the disaster.