Containment wells to form hydraulic barriers along site boundaries.

In the field, aquifer remediation methods include pump and treat procedures based on hydraulic control systems. They are used to reduce the level of residual contamination present in the soil and soil pores of aquifers. Often, physical barriers are erected along the boundaries of the target (aquifer) site to reduce the leakage of the released soil contaminant to the surrounding regions. Physical barriers are expensive to build and dismantle. Alternatively, based on simple hydraulic principles, containment wells or image wells injecting clear water can be designed and built to provide hydraulic barriers along the contaminated site boundaries. For brevity, only one pattern of containment well system that is very effective is presented in detail. The study briefly reports about the method of erecting a hydraulic barrier around a contaminated region based on the simple hydraulic principle of images. During the clean-up period, hydraulic barriers can considerably reduce the leakage of the released contaminant from the target site to surrounding pristine regions. Containment wells facilitate the formation of hydraulic barriers. Hence, they control the movement of contaminants away from the site that is being remedied. However, these wells come into play, only when the pumping operation for cleaning up the site is active. After operation, they can be filled with soil to permit the natural ground water movement. They can also be used as monitoring wells.

Intramuscular administration of 15(S) methyl prostaglandins F2 alpha for midtrimester abortion.

PIP: This study evaluated the clinical efficacy, safety, and side effects of intramuscular administration of 15(S) methyl F2 alpha for midtrimester pregnancy termination. 25 healthy women, generally in the 14-6th weeks of pregnancy, were given repeated doses of 250 mcg of 15(S) followed by 300-600 mcg at 2-3 hour intervals, depending upon the uterine contractions and side effects. In addition, 15 women were given Lomotil tablets before prostaglandin administration to counteract gastrointestinal side effects. The mean required dosage of prostaglandin was 2.3 mg. The induction-abortion interval was 5-10 hours in 32%, 11-15 hours in 52%, 16-20 hours in 8%, and 21-25 hours in 8%, with a mean abortion time of 13.04 hours. 23 women (92%) has complete and spontaneous abortion. Women treated with Lomotil experienced fewer episodes of vomiting and diarrhea. Other side effects included nausea in 40% of cases, cough in 12%, and fever in 16%. These side effects were mild and well tolerated by the patients, however. It is concluded that serial intramuscular injection of prostaglandin 15(S) methyl F2 alpha is an effective method for midtrimester abortion. In view of the minimal blood loss and asepsis associated with this method, it is particularly suitable for centers where blood transfusion facilities are inadequate.^ieng

Occupational noise exposure and hearing levels.

A study was made at the Bhabha Atomic Research Center to measure the hearing levels of persons working in a noisy environment. Two different workplaces, central air-conditioning plant and glass flowing shops, where a number of persons were exposed to noise levels exceeding 85 dB(A) were chosen. The occupational exposure to noise was determined using a sound level meter, an octave band filter and a personal noise dose meter. The hearing levels of persons exposed to these high levels of noise and a control group not exposed to occupational noise were measured by means of a pure-tone audiometer in a specially-build booth. These persons, aged between 20 to 60 years, were divided into four age groups for the study. The low ambient noise levels in the booth were measured using correlation technique since such low signals cannot be detected by an ordinary sound level meter. The audiometric findings and the results of the noise level survey are discussed in this paper.