A Proportionate Mortality Ratio (PMR) and Proportionate Cancer Mortality Ratio (PCMR) Analysis among Surinamese Residents Living in Proximity to Crude Oil Fields

ABSTRACT

Since crude oil exploration and extraction activities officially started in 1982 in Suriname, no environmental and health impact study have been conducted to determine whether residents living near petroleum production oil fields had adverse health effects. Internationally there have been some studies investigating the relationship between health effects and living in proximity of an oil field, but findings are still controversial whether crude oil exploration and extraction activities have negative health impacts on residents living in proximity of these oil fields. Therefore, we conducted a proportionate mortality ratio (PMR) analysis to determine if there were excess deaths due to a particular cause of death, particularly cancer, in residents with and without long-term exposure to crude oil exploration and extraction activities. Death certificates of the department of Epidemiology were used to gather mortality data (2002-2009) of the residents living near the Tambaredjo oil field (study population) while the mortality data of the general population of Suriname (reference population) was obtained using the reports of death causes in Suriname (2002-2009) provided by the department of Epidemiology. Proportionate mortality ratios (PMRs) and sex-adjusted proportionate cancer-specific mortality ratios (PCMRs) were calculated to evaluate excess death due to a particular disease or cancer type. PMRs for malignant neoplasm (1.19), external causes (1.26), and diabetes mellitus (1.27) were elevated while the PMRs for other major causes such as cardiovascular diseases (0.74), perinatal period (0.59) and HIV/AIDS (0.59) were decreased. Furthermore, elevated PCMRs for males were found for cancers of the stomach (1.46), liver (1.59), lung/bronchus (1.62), bladder (2.32), rectum (2.43), unspecified urinary tract (6.25), and testis (9.09). Elevated PCMRs for females were found for cancers of the cervix (1.27), lung/bronchus (1.76), brain/eye (4.39), and ill-defined gastrointestinal tract (11.76). We found several studies supporting our observed findings of cancer excess, but due to some study limitations such as the limitations of PMR analysis, the use of death certificates, and a small number of deaths in decedents of the study population; we could not conclude that our study findings were conclusive for a causal relationship. Therefore, we recommend more robust designs of studies to be undertaken, such as longitudinal and exposure assessment study designs, to associate exposure to crude oil exploring and extracting activities with adverse health effects, especially cancer, on the residents living near an oil field.