Association between oil spill clean-up work and thyroid cancer: Nine years of follow-up after the Hebei Spirit oil spill accident

In 2007, an unprecedented oil spill occurred in Taean, Korea. Although crude oil contains chemicals that could increase thyroid cancer risk, few studies have examined the long-term effects of oil exposure during clean-up and thyroid cancer incidence. We investigated the long-term thyroid cancer incidence among participants involved in clean-up work. 1798 participants engaged in at least two surveys since the baseline was tracked from 2008 to 2018. Participants reported the days they participated in oil clean-up works and cancer diagnoses. Cox proportional hazard models were used to estimate the hazard ratios between clean-up work duration and thyroid cancer. Over the 9-year follow-up, 30 thyroid cancer cases were diagnosed. A positive association was observed between clean-up duration and thyroid cancer risk. This effect was more pronounced among residents living <50 m from traffic roads. Our results indicate that crude oil clean-up work participation may increase the thyroid cancer risk.

Who has sustained psychological symptoms nine years after the Hebei Spirit oil spill?: The Health Effect Research on Hebei Spirit oil spill (HEROS) study

This study evaluated risk factors for sustained psychological symptoms in affected residents, nine years after the Hebei Spirit oil spill in Korea in 2007. The participants included residents of high-exposure areas, living within 2 km from the contaminated coast (n = 2013), among the cohort of the Health Effect Research on Hebei Spirit oil spill study from 2009 to 2016. Symptoms for post-traumatic stress disorder (PTSD), depression, psychosocial distress, and anxiety, as well as sociodemographic information were assessed through questionnaire interviews. Trajectory analysis was conducted to identify the group with sustained symptoms over time and logistic regression analysis was performed to identify risk factors for sustained symptoms adjusted for covariates. A longer duration of clean-up work, lower household income, and presence of a chronic disease in all type of symptoms, and being female, younger age, and higher educational level in all symptoms but PTSD, showed a significant association with increased risk of sustained symptoms. The highest risk was found in the subgroup with a longer clean-up together with offshore and maritime occupations or lower income in PTSD, depression, and anxiety, compared with those with a shorter clean-up and other occupation or higher income. Increased risk of sustained PTSD in relation to a longer clean-up was limited to those with a lower educational level (p-interaction = 0.009). The results suggested that participating longer in clean-up work increased sustained psychological symptoms, synergistically with socioeconomic factors such as offshore and maritime occupations, lower household income, or economic losses related to educational level.

Mosquito population dynamics during the construction of Three Gorges Dam in Yangtze River, China

BACKGROUND

Mosquitoes are responsible for spreading many diseases and their populations are susceptible to environmental changes. The ecosystems in the Three Gorges Region were probably altered because of changes to the environment during the construction of the Three Gorges Dam (TGD), the world's largest hydroelectric dam by generating capacity.

METHODS

We selected three sites at which to monitor the mosquitoes from 1997 to 2009. We captured adult mosquitoes with battery-powered aspirators fortnightly between May and September of each year in dwellings and sheds. We identified the mosquito species, and examined changes in the species density during the TGD construction. We monitored changes in the species and density of mosquitoes in this area for 13 years during the TGD construction and collected information that could be used to support the control and prevention of mosquito-borne infections.

RESULTS

We found that the mosquito species composition around the residential areas remained the same, and the density changed gradually during the TGD construction. The changes in the populations tended to be consistent over the years, and the densities were highest in July, and were between 3 and 5 times greater in the sheds than in the dwellings.

CONCLUSIONS

The mosquito species and populations remained stable during the construction of the TGD. The mosquito density may have increased as the reservoir filled, and may have decreased during the clean-up work. Clean-up work may be an effective way to control mosquitoes and prevent mosquito-borne diseases.