Marine Diesel Engine Exhaust Emissions Measured in Ship's Dynamic Operating Conditions

Occupational-related exposure to diesel exhaust and risk of leukemia: systematic review and meta-analysis of cohort studies

PURPOSE

Diesel exhaust (DE) is an established lung carcinogen. The association with leukemia is not well established. We conducted a systematic review and meta-analysis of cohort studies to determine the association between occupational DE exposure and risk of leukemia.

METHODS

A systematic literature review was performed to identify all cohort studies on occupational exposure to DE and associated risk of leukemia. STROBE guidelines and PECOS criteria were followed. Meta-analyses with fixed effects (and random-effects model in cases of high heterogeneity) were performed to calculate summary relative risks (RR) and 95% confidence intervals (CI), including subgroup analyses by outcome (mortality or incidence), sex, geographic region, industry type, and study quality. Study quality was assessed using the the Joanna Briggs Institute (JBI) critical appraisal checklist for cohort studies.

RESULTS

Of the 30 studies retained, 20 (8 from North America, 12 from Europe) reported a total of 33 estimates of the risk of leukemia. Overall, the relative risk (RR) of leukemia was 1.01 (95% CI = 0.97-1.05, I2 = 21.2%, n = 33); corresponding results for leukemia incidence and mortality were RR = 1.02 (95% CI = 0.98-1.06, I2 = 27.9%, n = 19) and RR = 0.91 (95% CI = 0.81-1.02, I2 = 0.0%, n = 15), respectively. The main results were confirmed in analyses by sex and geographic area. A statistically significant association was detected for miners (RR = 1.58, 95% CI = 1.15-2.15, I2 = 77.0%, n = 2) but not for other occupational groups. Publication bias was not detected (p = 0.7).

CONCLUSION

Our results did not indicate an association between occupational DE exposure and leukemia, with the possible exception of miners. Residual confounding cannot be excluded.

Comparison of the on Board Measured and Simulated Exhaust Gas Emissions on the Ro-Pax Vessels

Increasingly stringent environmental requirements for marine engines imposed by the International Maritime Organisation and the European Union require that marine engines have the lowest possible emissions of greenhouse and harmful exhaust gases into the atmosphere. In this research, exhaust gas emissions were measured on three Ro-Pax vessels sailing in the Adriatic Sea. Testo 350 Maritime exhaust gas analyser was used for monitoring the dry exhaust gas concentrations of CO2 and O2 in percentage, concentrations of CO and NOx in ppm and exhaust gas temperature in °C after the turbocharger at different engine loads. In order to compare and validate measured values, exhaust gas measurement data were also obtained from a Wartsila-Transas simulator model of a similar Ro-Pax vessel during the joint operation of the engine room and navigational simulators. All analysed main engines on three vessels had complete combustion processes in the cylinders with small differences which should be further investigated. Comparison of on board measured parameters with simulated parameters showed that significant fuel oil reduction per voyage could be accomplished by voyage and/or engine operation optimization procedures. Results of this analysis could be used for creating additional emission database and data-driven models for further analysis and improved estimation of exhaust gasses under various marine engine conditions. Additionally, the results could be useful to all interested parties in reducing the fuel oil consumption and emissions of greenhouse and harmful exhaust gases from vessels into the atmosphere.