Outbreak of Salmonella oranienburg infection in Japan

We experienced five cases of Salmonella oranienburg infection in children living in Saitama prefecture. Thereafter the number of patients with S. oranienburg infection increased not only in Saitama (55 cases) but also in other parts of Japan in 1999 (1505 cases) in 1999. The source of S. oranienburg infection was identified as a snack made from semi-dry cuttlefish.     

Increased binding of autoantibody to erythrocytes treated with cigarette smoke extract

When human erythrocytes were incubated with cigarette smoke (CS) exract for 1 h, the cells were oxidized as assessed by the decrease of cytoplasmic glutathione level. Because the ability of the CS extract pretreated with antioxidants and enzymes that destroy superoxide and hydrogen peroxide was lower, various oxidants in the extract may be responsible for the reduction of cytoplasmic glutathione levels. The binding of autologous IgG to the CS extract-treated cells as assessed by enzyme immunoassay was dramatically increased. Autologous IgG responsible for the binding may be anti-band 3 autoantibody, because inhibitors of anti-band 3 autoantibody binding effectively inhibited the IgG binding. The results indicate that oxidants in CS extract rendered erythrocytes susceptible to binding of anti-band 3 autoantibody, a known antibody that binds to senescent erythrocytes.     

Concentrations, enrichment and predominant sources of Sb and other trace elements in size classified airborne particulate matter collected in Tokyo from 1995 to 2004

APM was collected and trace elements existing in the particles were monitored since May 1995 in this study. APM sample was collected separately by size (d < 2 microm, 2-11 microm and >11 microm) on the roof of the university building (45 m above ground) in the campus of Faculty of Science and Engineering, Chuo University, Tokyo, Japan, using an Anderson low volume air sampler. The collected sample was digested by HNO3, H2O2 and HF using a microwave oven, and major elements (Na, Mg, Al, K, Ca and Fe) were measured by ICP-AES, and trace elements (Li, Be, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sb, Ba and Pb) were measured by ICP-MS. It was observed that the APM concentration was higher between the winter and the spring, compared to during the summer. The enrichment factor was calculated for each element in each set of APM (d < 2 microm, 2-11 microm and >11 microm). Seasonal trends of enrichment factors were examined, and the elements were classified into 3 groups according to the common seasonal behavior. It is likely that the elements in the same group have common origins. Toxic pollutant elements (Sb, Se, Cd, Pb and As) were found in small particles with d of <2 microm in concentrated levels. Antimony (Sb) had the highest enrichment factor, and the results suggested that Sb level in APM was extremely high. The origins of Sb were sought, and wastes from plastic incineration and brake pad wears of automobiles were suspected. Each set of APM (d < 2 microm, 2-11 microm and >11 microm) was classified by the shape, and the shape-dependent constituents of a single APM particle were quantitatively measured by SEM-EDX. High concentration of Sb was found in APM <2 microm and square particles. Particles less than 2 microm and square shaped particles were major particles produced by actual car braking experiments. From these experimental results it was concluded that the source of Sb in squared APM <2 microm is considered to be from brake pad wear.     

The cost of stratospheric climate engineering revisited

Stratospheric aerosol injection (SAI) has been receiving increasing attention as a possible option for climate engineering. Its direct cost is perceived to be low, which has implications for international governance of this emerging technology. Here, we critically synthesize previous estimates of the underlying parameters and examine the total costs of SAI. It is evident that there have been inconsistencies in some assumptions and the application of overly optimistic parameter values in previous studies, which have led to an overall underestimation of the cost of aircraft-based SAI with sulfate aerosols. The annual cost of SAI to achieve cooling of 2 W/m² could reach US$10 billion with newly designed aircraft, which contrasts with the oft-quoted estimate of “a few billion dollars.” If existing aircraft were used, the cost would be expected to increase further. An SAI operation would be a large-scale engineering undertaking, possibly requiring a fleet of approximately 1,000 aircraft, because of the required high altitude of the injection. Therefore, because of its significance, a more thorough investigation of the engineering aspects of SAI and the associated uncertainties is warranted.