supervision has found that they are thoroughly reliable in every respect. That point, together with the capping of the bottles, is one of the most important steps along this line. I believe that all bottles should be capped by machinery. That is the only way to safeguard this process, and I think it is the endeavor to make it as nearly foolproof as possible.

Dr. HARRY A. HARDING (Matthews Advertising Corporation, Detroit, Mich.). In the machinery that is used in the larger plants, especially that which runs from 6 to 10 hours, there can and does occur a piling up in the machine. This piling up adds to the bacterial count, particularly toward the latter part of the run.

Chairman WELD. The next paper will be the "Supervision of the Pasteurization of milk by State authorities," by Mr. H. A. Whittaker, director, Minnesota State Board of Health. This is a paper that will perhaps cover a great many of the points which some of you have in mind. I take pleasure in introducing Mr. Whittaker.

THE SUPERVISION OF THE PASTEURIZATION OF MILK BY STATE

AUTHORITIES.

HAROLD A. WHITTAKER, director, division of sanitation, Minnesota State Board of Health, Minneapolis, Minn.

Pasteurization is now recognized by health authorities as the most practical means of rendering market milk safe for human consumption. It is very gratifying to find that the general public is rapidly acquiring an appreciation of the importance of Pasteurization as a health measure; on the other hand, it is likewise discouraging to find that there are still a few active obstructionists to the process at the present time. These obstructionists are undoubtedly sincere in their conviction that it is possible to obtain a safe raw-milk supply under practical conditions. This ideal would be desirable if it were possible to attain it, but the cost of producing, handling, and supervising a raw-milk supply to meet the requirements necessary to insure safety is so great that it would place the price of the product above the reach of the average consumer. A study of the relative cost of the proper supervision of a raw-milk supply and a Pasteurized milk supply of a city of 20,000 population in the State of Minnesota, showed that it would cost several times as much to supervise the raw-milk supply in order to give the same relative protection from a health point of view. Even then, it is questionable whether the same protection could be guaranteed on the raw milk supply, since there are still many details in its supervision that have not been perfected to provide the necessary safeguards that would insure a safe product at all times.

The history of the application of purification to water supplies is somewhat analogous to that of the Pasteurization of milk. For many years, municipalities attempted to police the water catchment areas of surface water supplies in order to keep out every possible means of contamination. This was found to be exceedingly costly and difficult, since it required the control of extensive water catchment areas, and the maintenance of a large corps of sanitary inspectors to prevent the pollution of the supplies. It soon became evident that the most practical method of making surface water

supplies safe for public consumption was to apply some means of purification. The practice quite generally in use at the present time is to limit the pollution of surface waters which are used as sources of public water supplies to such an extent that the modern methods. of water purification can effectively remove any contamination which may be present in the raw water. This practice reduces the detail inspection work on the catchment area to a minimum and makes it possible to concentrate the supervision on the water purification plant where it can be more easily controlled.

The same practice is now applied to the supervision of milk supplies, particularly in the larger cities. It is impractical for most cities to provide the large number of inspectors necessary to carry on the supervision which would render raw milk reasonably safe; on the other hand, a limited number of inspectors can provide a reasonably clean product to the Pasteurization plants, and can concentrate their supervision on the Pasteurization process. The desirability of a raw-milk supply may be evident, but until some practical, inexpensive method of supervision for its protection can be devised, Pasteurization must remain as the greatest practical safeguard available for the protection of human health against the diseases transmitted through milk.

There are certain principles that should be observed in the production of a satisfactory Pasteurized milk supply. The following points are some which may be emphasized as of primary importance:

(1) The milk to be Pasteurized should be produced by healthy cows and handled in such a manner that it is not materially changed in composition by the action of bacteria or by the addition of foreign materials before it reaches the Pasteurization plant.

(2) The Pasteurization plant where the milk is processed should be properly constructed, and operated so that the entire treatment of the product, including Pasteurization, cooling, bottling, storing, etc., is satisfactory from a sanitary point of view. The same principles should apply to the methods of delivery to the consumer.

(3) The personnel of Pasteurization plants engaged in the production, Pasteurization, bottling, or cleaning of milk apparatus and utensils should be free from communicable diseases transmitted through milk as determined by the necessary medical and diagnostic laboratory examinations.

The milk consumer must have more protection than is provided by the individual dairyman and milk dealer. For this reason it is necessary that the supervision of the Pasteurization of milk be undertaken by State or local government units. These should be armed with the necessary legal authority to enforce the requirements, and they should be willing to cooperate with the producers and the distributors of the milk. It is most essential that State supervision be carried out in close coordination with local control. The States should have laws or regulations to cover the general essentials, but should leave the details of supervision to the local communities. The State law should authorize local government units, especially incorporated municipalities, to regulate their milk supplies under the general supervision of the State. It is advisable that the State laws and regulations should include general requirements for the dairies producing the supply, the Pasteurization plants, and the health of

the persons engaged in the Pasteurization and subsequent handling of the milk. These State laws or regulations should set minimum requirements which can be further elaborated by the local units. The duties of the State in most localities must be confined to general standardization, and to the specific regulation of physical conditions, such as the construction and equipment of dairies, Pasteurization plants, etc., rather than to the enforcement of operating procedure. It would be impossible for most States to make all of the detail requirements for general application throughout a State on account of the varying conditions, but it is possible to cover certain fundamentals. The State should be in a position to assist the local communities in initiating and establishing regulatory measures which are consistent with the State standards, and to cooperate with them in the enforcement of such enactments.

It may be of interest to outline the experience of the Minnesota State Board of Health in the supervision of milk Pasteurization in the State, the coordination of this work with local control, and the results obtained from these activities. An investigation of the supervision of the Pasteurization of milk from a health point of view was made in Minnesota during the year 1917. The information obtained at that time showed a need for immediate action in order to improve existing conditions.

The investigation included a detailed study of the Pasteurization plants, including their equipment and methods of operation, and the local supervision, if any, that was provided by the communities in which they were situated. These studies brought out certain important facts, which may be summarized briefly as follows: Pasteurization, in most instances, was not carried on as a health measure, but simply to improve the keeping quality of the milk or as an advertising feature. The latter may be illustrated by the fact that five plants were found labeling their product "Pasteurized milk" when they did not own any Pasteurizing apparatus. Many of the Pasteurization plants were not constructed so that the milk could be effectively Pasteurized. Defects in construction were found both in the buildings and in the plant equipment. As an illustration, not a single plant, except those in the three largest cities in the State, was equipped with a recording thermometer, and the dairy thermometers which were in use at many of these plants were found to register incorrectly from 1° to 10°. Many of the plants were operated by men who had little, if any, appreciation of the health significance of the Pasteurization process. Not a single community was found in the entire State where the employees, engaged in processing the milk at the Pasteurization plants, were required to pass a medical examination to determine that they were not chronic carriers of infectious diseases transmitted through milk. No local supervision was found except in the case of a few of the largest cities. Very few of the municipalities had ordinances regulating their milk supplies, and these ordinances in most instances did not contain provisions regulating the Pasteurization of milk.

The writer wishes to acknowledge the excellent work of Dr. R. W. Archibald, bacteriologist of the division of sanitation, Minnesota State Board of Health, whose efforts have contributed so much to the success obtained in the improvement of Pasteurized milk supplies in Minnesota.

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These investigations showed very conclusively that the unsatisfactory conditions were largely the result of inadequate supervision on the part of the State and local communities, and should not be charged against the milk dealers.

The State board of health took the following steps toward improving these unsatisfactory conditions: The State departments interested in the milk-supply situation were called together to develop a plan for the coordination of their activities and to discuss the best means of starting a campaign to improve conditions. It was decided that the most important step was to provide an ordinance for local adoption. An ordinance adaptable to all but the three largest cities in the State was prepared and approved by these State departments. Regulations were passed by the State board of health which defined Pasteurization, required the approval of plans and specifications on all new Pasteurization plants, required the medical examination of certain employees at Pasteurization plants, and prohibited insanitary conditions at Pasteurization plants.

The division of sanitation of the State board of health was instructed to begin an active campaign to improve milk supplies throughout the State. The work included propaganda toward establishing local supervision of milk supplies and the general supervision of Pasteurization plants.

The activities directed toward establishing local supervision included: (1) The distribution of literature on milk in relation to public health, to attract attention to the problem; (2) assistance to local officials and organizations in the investigation of municipal milk supplies in order to determine their sanitary condition; (3) aid in the passage of the milk ordinance approved by the various State departments; and (4) assistance to municipal officials in organizing the details of local supervision after the ordinance had been passed. The work on existing Pasteurization plants covered an investigation of each installation to determine whether or not the equipment of the plant and the methods of operation were satisfactory. In the case of new plants the regulations require the approval of plans and specifications before construction is begun so as to prevent unsatisfactory buildings and equipment. In all cases where defects in equipment or operation were found, specific recommendations were made for their correction. Follow-up investigations were made on all plants as soon as notice was received that the recommendations had been carried out. It was the policy of the division of sanitation to turn over the detail supervision of the operation of the plant to local officials just as soon as the equipment of the plant and the methods of operation were found to meet the requirements of the State board of health. In cases where no ordinances had been passed to provide for local supervision, an effort was made to establish local super

vision.

The division of preventable diseases of the State Board of Health cooperated with the supervision work on the medical examination of personnel at Pasteurization plants. The medical examination was confined to those persons engaged in the Pasteurization, bottling, or cleaning of milk apparatus and utensils. The examination, required by the division of preventable diseases, includes an inquiry into the communicable disease and vaccination history of applicant, and a

physical examination, to exclude acute and chronic infections, both superficial and deep seated. The taking of nose and throat cultures is a routine procedure to exclude diphtheria carriers. The Widal test is also made as a matter of routine, and whenever the Widal reaction is present or atypical, or there is a history of typhoid fever, bowel and bladder discharges are examined to exclude carriers of typhoid infection. If tuberculosis, syphilis, or other acute or chronic infection is suspected, the proper laboratory examinations are made. In addition, the owner is required to exclude from work any employee suspected of having any acute infection, including sore throat, "cold," or minor purulent affection of skin or mucous membranes and to report the same immediately to the health officer.

These activities have been carried on since 1918, with the result that 65 municipalities have passed the proposed milk ordinance recommended by the State departments; the equipment and methods of operation of all of the Pasteurization plants, under the jurisdiction of the State board of health, have been approved, or the owners have been required to discontinue labeling, advertising, and selling their product as "Pasteurized milk.”

Investigations made on the plants since this supervision was established have shown a marked improvement in the routine methods of Pasteurization and in the sanitary quality of the milk. Before supervision was established, the bacterial counts of the Pasteurized milk from most of the plants varied from one to several million; since improvements have been made at these plants, the counts run quite consistently below 50,000 per cubic centimeter.

The principal reason why any department of the Government is interested in the supervision of the Pasteurization of milk is that such supervision affords protection to the public from diseases that may be transmitted through milk. The question is sometimes raised as to which department of the State or local government should be assigned the duty of supervising the Pasteurization of milk. It would be folly for anyone to lay down an arbitrary rule, specifying the particular branch of the Government that should be charged with the responsibility of the sanitary supervision of milk supplies, since conditions vary throughout the country. Most State boards or departments of health are equipped with administrative officers, and with subdivisions which undertake the necessary technical and educational activities that can be coordinated to bring about effective supervisory and enforcement work. They are equipped with divisions of sanitation or sanitary engineering, employing personnel who can deal with the problems involved in the construction and operation of Pasteurization plants, including the approval of plans and specifications of new installations, and routine investigations on existing plants; divisions of preventable or communicable diseases, employing trained epidemiologists to supervise the medical examination and personal hygiene of the employees at dairies and plants, and to investigate the communicable diseases that may be associated with milk supplies; divisions of child hygiene, public health education, and public health nursing, employing educational workers, trained nurses, social workers, etc., who are in a position to carry on educational work, which will create a desire on the part of the communities to improve their milk supplies, and to teach an appreciation of the