Latent Trajectories of Haematological, Hepatic, and Renal Profiles after Oil Spill Exposure: A Longitudinal Analysis.

Exposure to polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs) in crude oil has carcinogenic effects on various organ systems. This longitudinal cohort study examined the effects of oil spill exposure on the haematological, hepatic, and renal profiles of Rayong oil spill clean-up workers. The sample included 869 clean-up workers from the Rayong oil spill. Latent class mixture models were used to investigate and classify the longitudinal trajectories and trends of the haematological, hepatic, and renal indices. Subgroup analysis was used to evaluate the association between the urinary metabolites of PAHs and VOCs and haematological, hepatic, and renal parameters. Most clean-up workers (97.6%) had increasing levels of white blood cells (WBCs) (0.03 × 103 cells/µL), 94.90% of the workers had a significantly increasing trend of blood urea nitrogen (0.31 mg/dL per year), and 87.20% had a significantly increasing trend of serum creatinine (0.01 mg/dL per year). A high-decreasing trend of WBCs was seen in 2.42% (-0.73 × 103 per year). Post-exposure changes in haematological, renal, and hepatic profiles are present in workers exposed to the Rayong oil spill. This indicates possible long-term health complications and worsening renal function after exposure to PAHs and VOCs in crude oil.

Haematological, renal, and hepatic function changes among Rayong oil spill clean-up workers: a longitudinal study.

PURPOSE: The Rayong oil spill incident of 2013 leaked over 50,000 barrels of crude oil into the Gulf of Thailand. This study assessed trends and changes in the haematological, renal, and hepatic indices among the Rayong oil spill clean-up workers 5 years after the spill. METHODS: Haematological, renal, and hepatic indices measured for 570 oil spill clean-up workers at baseline and annually during 5-year follow-ups were analysed. Haemoglobin (Hb), haematocrit (Hct), white blood cell (WBC) count, red blood cell (RBC) count, and platelet count for haematological function, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) for hepatic function, and creatinine (Cr) and blood urea nitrogen (BUN) for renal function were assessed. The longitudinal measures of haematological, renal and hepatic indices were analysed using analysis of variance for repeated measures. The generalised estimating equations (GEE) were used to assess trends of these indices and associated factors, including exposure level. RESULTS: Increasing trends were observed per year for WBC (0.52 ± 0.03 × 103 cells/µL), Cr (0.01 ± 0.00 mg/dL), platelet (0.31 × 103 µL per year), and BUN (0.24 ± 0.03 mg/dL). Decreasing trends of aspartate aminotransferase (AST) were observed (1.54 ± 0.21 IU/L per year). Clean-up workers with high exposure to the oil spill had a significantly higher average of WBC and lower average of BUN than low-exposure and unknown-exposure workers. Gender and age were significantly associated with creatinine changes. CONCLUSION: Results of this study show the differences between baseline and follow-up haematological, renal, and hepatic indices and trends of these indices. The long-term changes in the indices in this study show worsening renal functions after oil spill and possibility of cardiovascular effects. These findings contribute to expanding knowledge on the long-term health effects of oil spills.

EXPOSURE ASSESSMENT OF RAYONG OIL SPILL CLEANUP WORKERS.

Background: In July of 2013, a pipeline connecting an offshore oil platform to a tanker caused crude oil to spill into the Sea of Rayong off the coast of Thailand. The resulting oil slick, estimated to be between 50 and 190 cubic meters (336-1,200 barrels), washed ashore one day later on the island of Samet. We conducted a study to quantify internal dose of polycyclic aromatic hydrocarbons (PAHs) and benzene in 1,262 oil spill cleanup workers, and to examine factors related to their dose. Methods: Frozen stored urine samples (n=1343) collected from the workers during the one month cleanup period were used to measure the concentration of 1-hydroxypyrene-glucuronide (1-OHPG), cotinine and creatinine. Data from questionnaires and urinary trans,trans-muconic acid (t,t-MA), a benzene metabolite, measured previously as part of a worker health surveillance plan, were linked with the laboratory data. Results: The internal dose of urinary 1-OHPG was highest in individuals who worked during the first 3 days of cleanup work (median: 0.97 pmol/ml) and was 66.7% lower (median: 0.32 pmol/ml) among individuals who worked in the final week of the study (days 21-28). After adjusting for age, cotinineand creatinine by regression analysis, the decline in urinary 1-OHPG concentration with days of cleanup remained significant (P-trend <0.001). A decreasing trend by days of cleanup was also observed for detectable urinary t,t-MA percentage (P-trend <0.001). Conclusion: Rayong oil spill cleanup workers exhibited evidence of elevated levels of PAH and benzene exposure during the early weeks of cleanup, compared to near background levels 4 weeks after cleanup began. Long-term health monitoring of oil spill cleanup workers is advised.