as breast,11lung, renal, and nasal cancers.35Noncarcinogeniceffects of benzene exposure include respiratory abnormalities,deteriorated renal function, central nervous depression, skinirritation, hepatotoxicity, myelotoxicity, hematologicalalterations, and immunotoxicity.18Previously, we reported that benzene exposure significantlyaltered the hematological and hepatic functions in children,adults, and elderly subjects.23-28In addition, recently wereported that children exposed to benzene experienced arange of illness symptoms and an altered profile of urinaryphenol, suggesting their vulnerability to increased adversehealth complications.29The analyses in this study sought tofurther assess the illness symptom profiles following benzeneexposure from the prolonged toxic release of the BPflaringevent in adults, building on our earlier studyfindings.Thefindings of this study show that adult subjects exposed tobenzene from the BPflaring event experienced a wide rangeof adverse health symptoms including neurological, respira-tory, cardiac, dermatological, gastrointestinal, and a host ofother adverse symptoms. Each benzene-exposed adultexperienced multiple adverse neurological symptoms suchas headaches, memory loss, unsteady gait, and dizziness.Similarly, multiple upper respiratory symptoms such asshortness of breath, sore throat, difficulty in breathing,bronchitis, nose bleeds, hoarseness, and sinusitis were seen ineach benzene-exposed subject. Over 25% of the subjectsexperienced cardiac, gastrointestinal, and dermatologicalsymptoms; painful joints; diarrhea; and cough followingtheir exposure to benzene. Currently, the literature is sparseevaluating the adverse health symptoms of benzene exposurein adults or children. A study by Gordian et al36reported thatresidents exposed to evaporative emissions of gasoline hadmore severe symptoms of asthma affecting their respiratoryhealth. Tunsaringkarn et al37reported that gas stationworkers who were exposed to benzene experienced healthsymptoms such as dizziness, headache, skin irritation, eyeirritation, fatigue, sore throat, nausea, and depression. Thefindings of our current study are comparable with thosefindings reported by Tunsaringkarn et al37in that significantproportions of subjects experienced these adverse healthsymptoms following their exposure to benzene.To determine whether the subjects’gender contributed to theobservedfindings, we assessed and compared the incidence ofadverse health symptoms between male and female subjectsexposed to benzene. The overall frequency of adverse healthsymptoms was higher in women (5.5 symptoms per femalesubject) than in men (5.0 symptoms per male subject).Previously, we reported that the overall frequency of adversehealth symptoms was higher in female children (2.9 symp-toms per female child) than in male children (2.7 symptomsper male child).29Thesefindings collectively suggest thatfemale subjects are more vulnerable than male subjects to theeffects of benzene exposure. Multiple regression analysis was
consequences and the significance of the elevated urinarylevels of phenol in subjects exposed to benzene.
Limitations
Our study had some limitations and the studyfindings shouldbe interpreted as such. Foremost, this study was conductedby use of a cross-sectional design. This study design allowsonly for generating a hypothesis for further investigation andnot for investigating causality. The major limitation was alack of baseline data prior to theflaring event at the BPrefinery. In addition, this investigation was retrospective innature. Thus, it is difficult to infer causality using such a studydesign because the outcomes were measured at one time pointafter exposure to benzene. The major limitation was the lackof the subjects’baseline data prior to theflaring event at theBP refinery. Moreover, there may have been a self-report biasof our outcome classification, as the subjects were aware ofthe benzene pollution in their community. This may haveresulted in an overestimation of the reported outcomes. Tominimize this potential bias, study subjects who reportedexperiencing any adverse health symptoms were asked todescribe the health symptoms to the interviewers.
Regardless of these limitations, the results of our studyindicate that benzene exposure from the refinery disaster wasassociated with significant adverse health effects among thoseexposed subjects. Since benzene is a carcinogen, people whowere exposed to the benzeneflaring disaster need to befollowed periodically over time to detect any long-term orprogressive abnormalities and adverse health complaints.Periodic health checkups, including routine laboratory blood,pulmonary, cardiac, neurologic, and other organ functionevaluations, should be performed to monitor the long-termadverse health consequences of their benzene exposure. Thus,future longitudinal studies are required to explore theimportance and nature of the health effects on humansexposed to benzene.
CONCLUSION
Together, the results of this retrospective study indicate thatsubjects exposed to benzene experienced a broad range ofadverse health symptoms including neurological, respiratory,and cardiac symptoms; painful joints; gastrointestinal symp-toms; and dermatological symptoms. In addition, a majorityof these subjects reported cough, diarrhea, nausea/vomiting,and other adverse health symptoms following their exposureto the benzene BPflaring disaster. Thesefindings support ourprevious studyfindings in which we reported that subjectsexposed to benzene experienced significant and adversealterations in their vital organ functions, including hemato-logical, hepatic, and renal functions.8-23It is therefore crucialto monitor these subjects on a long-term basis to detectadverse toxicities of their benzene exposure, especially thedevelopment of secondary malignancies. Further prospectivestudies are required to understand the potential adverse