Relationship of hemoglobin to occupational exposure to motor vehicle exhaust

Clinical manifestations of lead workers of Mangalore, India

Objective: To correlate blood lead levels and clinical manifestations. Participants: Battery workers and painters (occupationally exposed to lead in and around Mangalore, India) and occupationally unexposed controls. Main outcome measures: We measured the blood lead levels by anodic stripping voltammetry, and a clinical examination was carried out on all participants. Results: There was a statistically significant difference between the lead-exposed group and controls with respect to clinical manifestations. The prominent findings among the lead-exposed group were fatigue, abdominal colic, abdominal discomfort, backache, muscular exhaustability, myalgia and paresthesia, at a blood lead level ranging from 0.4 to 116.6 μg/dL. Conclusions: Such a study on battery workers and painters has not been reported in India. Several attempts have been made over the years to relate blood lead levels to adverse health effects. It was not possible to determine a precise blood lead level below which symptoms never occur or a blood lead level at which symptoms are always reported. Toxicology and Industrial Health 2006; 22: 405-413.

Benchmark dose of lead inducing anemia at the workplace

To estimate the critical dose of lead inducing anemia in humans, the effects of lead on hemoglobin (Hb) and hematocrit (Hct) levels and red blood cell (RBC) count were examined in 388 male lead-exposed workers with blood lead (BPb) levels of 0.05-5.5 (mean 1.3) micromol/L by using the benchmark dose (BMD) approach. The BPb level was significantly related to Hb (regression coefficient beta=-0.276), RBC (beta=-11.35), and Hct (beta=-0.563) among the workers (p < 0.001) when controlling for age and working status. The average BPb levels were significantly higher in the workers with anemia (1.85 micromol/L), based on the WHO criteria, than in those without anemia (1.26 micromol/L). The benchmark dose levels of BPb (i.e., lower 95% confidence limits of BMD), calculated from the K-power model set at an abnormal probability of 5% in unexposed workers and an excess risk of 5% in exposed workers were estimated to be 0.94 micromol/L (19.5 microg/dl) for Hb, 0.94 micromol/L (19.4 microg/dl) for RBC, and 1.43 micromol/L (29.6 microg/dl) for Hct. These findings suggest that reduction in hematopoietic indicators may be initiated at BPbs below the level currently considered without effect.

Determination of carboxyhemoglobin levels and health effects on officers working at the Istanbul Bosphorus Bridge

Urban air pollution is a problem throughout the world. Carbon monoxide (CO), one of the major air pollutants, is an odorless, colorless, tasteless, and toxic gas, which is mainly produced by incomplete combustion of the fossil fuels such as gasoline and kerosene. The main outdoor sources of CO gas are vehicle exhausts, industrial effluents, and fires. When inhaled CO gas causes occupational hazards especially on workers who work at the junctions of heavy traffic roads and at the inefficiently ventilated closed areas such as parking garages and car repair shops. The purpose of this research was to determine the relation between carboxyhemoglobin (COHb) and CO levels and its health effects on cashiers working at the Istanbul Bosphorus Bridge. In the research the carbon monoxide and carboxyhemoglobin levels in the alveolar air of the numbers of the test group and the control group were measured and a questionnaire consisting of questions related to the personal information, their habitats as smoking or not smoking and the health conditions of the test and control group members were filled by interviewing them. The data obtained was analyzed by using Microsoft Excel Table Graphic Program, Chi-Square (2) Test and the Student-t Test. The results indicated that smokers are affected more by the CO than the nonsmokers.

Lead exposure in battery-factory workers is not associated with anemia

Anemia is a manifestation of lead toxicity. However, there are conflicting reports of its prevalence among lead-exposed workers, and it is uncertain whether they should be monitored by periodic hemoglobin (Hb) examinations. To explore the relationship between Hb and lead exposure, we examined the correlation between Hb, blood lead (PbB), and zinc protoporphyrin (ZPP) levels in 961 blood samples obtained from 94 workers in a lead-acid battery plant in Israel between 1980 and 1993. Blood lead levels exceeded 60 micrograms/dL (2.90 mumol/L) in 105 (14%) of the blood samples. The correlation between PbB and logZPP was 0.594. Hb levels did not correlate with PbB or ZPP. We conclude that (a) periodic Hb determinations are not a useful indicator of lead exposure in Israeli industrial workers; (b) the discrepancies between the reported correlation between PbB and Hb levels remain unexplained and in need of further study; and (c) a finding of anemia in a person with PbB levels of up to 80 micrograms/dL should be considered to be due to lead toxicity only after other causes for anemia have been excluded.