Dose-Response Assessment of Airborne Methyl Isothiocyanate (MITC) Following a Metam Sodium Spill

A tank car derailment in northern California in 1991 spilled metam sodium into the Sacramento River, and released its breakdown product, methyl isothiocyanate (MITC), into the air. This paper describes the risk evaluation process used. Over 240 individuals reported symptoms such as eye and throat irritation, dizziness, and shortness of breath. Reference exposure levels (RELs) for 1 hr were developed for MITC and compared to exposure concentrations. Ocular irritation in cats was the most sensitive endpoint reported. The no observed adverse effect level (NOAEL), divided by an uncertainty factor (UF) of 100, produced an REL of 0.5 ppb of MITC in air to prevent discomfort. An REL to prevent disability was estimated to be 40 ppb. An REL to prevent life-threatening injury was estimated to be 150 ppb. Measured MITC levels ranged from 0.2-37 ppb and estimated peak levels ranged from 140-1600 ppb. The usefulness of RELs for emergency planning is discussed.     

Forthcoming in Sociological Forum

Volume Contents

Forthcoming in Sociological Forum     

Effect of the doctor on college students' attitudes toward physician-assisted suicide

Ninety-six students were presented with eighteen different vignettes describing different types of active and passive observed suicide, assisted suicide, and euthanasia. Attitudes regarding the morality and desired legality of each situation were measured. Results indicated that the interaction between the doctor and the patient, and, to a lesser extent, the active or passive nature of the agent of death, were more important than the actual actions of the doctor in allowing or causing death to occur.     

Alternative Question Forms for Attitude Scale Questions in Telephone Interviews

The absence of visual aids in telephone interviews has led investigatorsto seek methods for asking questions which are commonly accompaniedby aids in personal interviews. This study experimentally comparedtwo approaches to asking seven-point scale attitude questionsin a national (N = 4,300) telephone health survey. A randomhalf-sample received the attitude questions as single-step numericalselection tasks. The questions were administered to the otherhalf-sample in two stages, the first asking for a general verbalstatement of attitude and the second asking for a more detailedspecification. The two question forms produced comparable resultsin univariate distributions. Items administered with the one-stepform showed slightly higher intercorrelations. This study representsone step in the process of empirically testing data collectionprocedures which have been deemed necessary in the rich folkloreof survey research. Overall, the results show more comparabilitythan might be anticipated, given the multiple differences betweenthe forms.     

The marriage squeeze

If the sex-age structure of the population is equilibrated, observed marriage patterns are assumed to reflect preferred mate selections. With regard to age, these preferences can be expressed in terms of the probabilities of unmarried persons of given ages marrying persons of various ages. To study the situation of unequilibrated sexes, these probabilities can be used to compute, for each combination of ages of groom and bride, the expected number of grooms and the expected number of brides. If either of these numbers exceeds the other, the corresponding sex is in a "marriage squeeze." The comparison among the expected number of grooms, that of brides, and the observed number of marriages supplies information on the effects of the squeeze.In Australia, marriage statistics of 1949 were considered to reflect preferred selections. In 1958, men of most ages were in a squeeze. As a consequence, some relatively younger and older men did not get married, and some relatively younger and older women improved their chances of marriage in the year under consideration. 291-299.     

Projective (2n,n,λ,1)-designs

A projective (2n,n,λ,1)-design is a set $\text{D}$ of n element subsets (called blocks) of a 2n-element set V having the properties that each element of V is a member of λ blocks and every two blocks have a non-empty intersection. This paper establishes existence and non-existence results for various projective (2n,n,λ,1)-designs and their subdesigns.