censuses show that more public health nurses are being employed to teach child hygiene courses in colleges and universities that prepare public school teachers.

During the 15 years covered by the census, including the war period, there has been encouraging improvement in the provision of fulltime public health nursing services in rural areas. In 1938, there were 1,057 counties providing no full-time public health nurses for their rural areas, but in 1953 the number had declined to 671.

Engineers and New Environmental Problems

Since sanitary engineers and sanitarians play an important role in the improvement of man's environment, the Public Health Service, through the Division of Engineering Resources, continued its interest in the supply and qualifications of these essential health workers. The Nation's shortage of engineers, including sanitary engineers, continued in 1953. However, the ratio of graduates in sanitary engineering to total engineering graduates was greater in 1952 than in any year since 1940. In the postwar years there has been a substantial increase in the number of master's and doctor's degrees awarded in sanitary engineering. The figures for 1952 show a higher rate of increase in the number of master's degrees awarded than in the corresponding rate for the bachelor's degree.

A study was undertaken-in conjunction with the Division of Public Health Education-to identify the factors which influence the choice of sanitary engineering as a career and which operate to keep graduates in the field. During the year, interviews were completed with 190 sanitary engineers who graduated within the 40-year period 1910-1949 and with 86 students majoring in sanitary engineering. A previous study had shown a high rate of loss to the profession, in that 51 percent of the graduates are currently employed in fields other than sanitary engineering. The chief factor which brings about the change was found to be the failure to enter the field immediately upon graduation-usually because of the lack of job offers. Since there are sanitary engineering jobs available in increasing numbers, the problem comes down simply to compiling job information and making it available to college seniors by the middle of the academic year.

A study of undergraduate education for sanitarians was completed in 1953. Sixteen colleges and universities now offer training in sanitary science at the undergraduate level. All but four of these courses have been initiated since World War II. Since 1931, 397 men have graduated with a major in sanitary science; of these, 364 completed their undergraduate work since the end of the war.

RADIOLOGICAL HEALTH

The Division of Engineering Resources assists State and local health agencies in developing radiation control methods and in training their personnel to play an essential role in dealing with radiological health problems. During the year, a team composed of Public Health Service and New Jersey State Department of Health personnel completed a survey of the sources and locations of excessive radiation exposure in New Jersey. A pilot demonstration on the control of such exposures, especially in industry, is being developed and control methods are being put into effect.

A group of 35 Public Health Service officers participated in the Off-Site Monitoring Program conducted by the Atomic Energy Commission and the Department of Defense during the tests of atomic weapons in Nevada during 1953. A substantial amount of data was collected for the assessment of the possible health hazards in atomic debris.

HYGIENE OF HOUSING

A study comparing housing conditions revealed in the 1950 Census with those revealed in 1940 showed that there has been no change for the better in certain housing deficiencies. Approximately the same. number of dwellings (2 million) were rated as overcrowded in both. years, while the same number of dwellings (7.4 million) were without private flush toilets. As of January 1, 1953, 10 State health departments and about 100 local health agencies had actual housing programs.

DEFENSE COMMUNITY FACILITIES

The Defense Housing and Community Facilities and Services Act of 1951 (P. L. 139, 82d Congress) was extended by Congress for one year. Funds for Public Health Service assistance to communities, however, were exhausted by December 31, 1952. During the period that appropriations were available, the Public Health Service allocated $7,944,414 to 33 eligible communities in 20 States for 33 sanitary engineering projects and 6 hospital projects. The total construction cost-Federal and local-of the sanitary engineering projects is estimated to amount to $15,117,257; of the hospital projects, $5,995,223. When completed these projects will provide 6 hospitals, 23 sewage disposal plants, 11 water treatment facilities, and equipment for 1 refuse disposal project.

Interstate Problems in Sanitation

The Division of Sanitation is responsible for those Public Health Service activities designed by Congress to protect the public from

insanitary conditions to which they may be exposed in interstate travel. These include the maintenance of sanitary conditions aboard trains, planes, and buses operating across State lines, as well as aboard American flag vessels in foreign and interstate commerce. In addition, the Division reviews plans for the construction of new conveyances and servicing facilities so that proper sanitation standards may be maintained. The Division also cooperates with the States and the industries concerned to maintain the sanitary quality of milk, milk products, and shellfish that are shipped across State lines.

MILK SANITATION

Laboratory studies have been completed in a cooperative research project with the University of California to determine the time-temperature combinations necessary to destroy the organisms of Q fever. The project has been supported in part by the Milk Industry Foundation and the Dairy Industries Supply Association. During the coming year, the laboratory findings will be tested under conditions. simulating commercial pasteurization.

The National Program for Interstate Milk Shipments continued to expand during the year. By June 30, 1953, 358 interstate shippers located in 30 States were participating on a voluntary basis. Through joint certification of these supplies by the Public Health Service and the States, both the shippers and the communities requiring imported milk supplies will benefit. The Public Health Service also cooperated with the International Association of Milk and Food Sanitarians and the Sanitary Standards Subcommittee of the Dairy Industry Committee in the development of new standards for dairy equipment. The work of this group has saved the milk and milk-products industries many thousands of dollars every year.

PROTECTION OF TRAVELERS

Nearly 2 million persons travel on trains, planes, and ships in the United States each day. To make sure that the food and water served aboard these interstate carriers are safe, the Public Health Service and cooperating State health departments in 1953 inspected more than 1,200 water supplies, 3,000 watering points, 600 milk sources, 400 sources of frozen desserts, and 400 commissaries. Certificates of Sanitation were also awarded to 617 vessels. The average sanitation rating achieved by all railroad dining cars in 1953 was 88.5 percent, as compared with 86.7 percent in 1952. This year, the Erie Railroad became the first major railroad to receive a Certificate of Sanitation for every one of its dining cars.

SPECIAL PROJECTS

At the request of the National Council of the Boy Scouts of America, the Public Health Service assigned medical and sanitary engineer officers to plan and supervise the public health provisions for the 1953 Jamboree at Santa Ana, Calif. Fifty thousand boys were expected to travel from all parts of the country at the peak of the vacation season. Difficult problems had to be anticipated and solved with respect to adequate and sanitary dining-car and sleeping-car service, sanitary facilities at the camp site, inspection of milk, frozen desserts, and other food supplies, and control of communicable diseases. The Division of Sanitation also cooperated with the Health Department of the District of Columbia in safeguarding the health of about 8,000 persons who lived in Pullman cars in the railroad yards during the week of the Inauguration of President Eisenhower.

HOME ACCIDENT PREVENTION

The Public Health Service continued its close cooperation with the National Safety Council, the States, and other agencies in a concerted effort to reduce deaths and serious disabilities due to home accidents. In January 1953, the University of Michigan School of Public Health was host to the First National Conference on Home Accident Prevention, with the National Safety Council and the Public Health Service as co-sponsors. The Conference was attended by more than 100 key workers in home accident prevention, representing Federal, State, and local agencies, voluntary associations, and various industries.

A study of home accidents initiated by the Public Health Service in Washetaw County, Mich., has been completed. It provides muchneeded data on the causes, frequency, and severity of such accidents. During the past two years, the W. K. Kellogg Foundation has been financing four demonstrations in home accident prevention as a function of the local health department. These projects were planned and supervised by the Public Health Service, and are now being operated without assistance by the local health departments in Cambridge, Mass., Mansfield, Ohio, Kalamazoo, Mich., and San Jose, Calif. The success of these pilot studies has resulted in the allocation of funds by the Foundation for demonstrations of State home accident prevention programs in the health departments of California, Georgia, Kansas, Kentucky, Maryland, Massachusetts, North Carolina, and Oregon.

Research on Environmental Problems

The Environmental Health Center at Cincinnati, Ohio, made several outstanding contributions through its research and development program during the year. The Center also continued its field investigations, training program, and special services to the States.

DETECTION OF EXOTIC CHEMICALS

One of the most perplexing and costly problems for municipal engineers is the presence in water supplies of chemicals from industrial wastes. These substances are not eliminated in ordinary water treatment processes and it has been impossible up to the present time even to identify and measure them. In some cities, the cost of treating the water to overcome undesirable effects is prohibitive, and the available methods are not fully successful in reducing the offensive odor and taste imparted by the chemicals. As yet, relatively little is known. about the effects of these extraneous substances on human health.

During the year, the Environmental Health Center developed a method to identify and measure some of these chemicals. The method is based upon the ability of the chemicals to absorb infra-red light. It was found that even microscopic quantities react in a characteristic pattern. The results of this research should lead to the development of standard curves for chemicals in industrial wastes. The practical outcome would be that city engineers could quickly and economically identify the offenders. Then, referring to their State inventories of industries discharging wastes into the water source, they could promptly bring about control.

At present, the Center is studying the applicability of the infrared technique to the rapid identification of classes of bacteria. If this proves feasible, the potential value of the membrane filter will be greatly enhanced. Although the filter provides a simple means of collecting bacteria in water supplies for examination, the lack of a rapid means of identification of the micro-organisms has restricted. its potential value in combating the massive contamination of water supplies by natural disasters or enemy action. The usefulness of the infra-red technique will also apply to combating chemical contamination of water supplies in emergencies.

RADIOACTIVE WASTES

Laboratory experiments and tests in a pilot water plant were made at the Oak Ridge National Laboratory to determine the efficiency of various processes for removing radioactive wastes from water. So far, it has been found that the processes used in the majority of municipal waterworks are of limited effectiveness.

A study was made at the request of the Utah State Health Department to determine whether radiation exposures were the cause of unexplained deaths of sheep grazing in the southwest part of the State. The results showed significant exposure of the animals to radiation, particularly as evidenced by radioactive iodine in the thyroid tissues. However, the findings neither confirm nor deny the possibility that the deaths were due to fall-out of fission products in the testing of