Environmental health programs do not deal directly with individuals but rather with those aspects of the environment that contain threats to human health. The programs discussed here include sanitation control, hazard control, and health promotion. The objects of sanitation control are in the natural environment--food, air, water, soil, rodents and insects--and such pollutants of the environment as garbage, sewage, and industrial wastes. Sanitation programs have probably accomplished more to improve man's surroundings and reduce infectious disease than any other endeavor in the field of public health. The objects of hazard control are in the man-made environments of shelter, transportation, and industry. Sanitation and hazard control programs are protective, erecting barriers between man and disease or injury. Some of these programs are among the oldest health activities in the country. In recent years the concept has gained acceptance that control of the environment should go beyond the prevention of disease and injury, to the promotion of good health. The treatment of water with fluorides is an outstanding example of health promotion.
Authorities in the fields of health and engineering are no longer faced with many of the theoretical problems in the control of environmental health hazards. Filter plants, chlorination plants, facilities for incineration and pasteurization, and the biochemical techniques, are established means of control. The manufacturing and marketing of food products are subject to extensive inspection and regulation. Methods of controlling and eradicating many of the dangers of industrial poisons are known, although substances new to industry call for extended research.
The magnitude of the problems of controlling diseases by means of controlling the environment is indicated by the following morbidity and mortality data:
Typhoid, a filth-borne disease, was a major cause of death in 1900, when it accounted for 23,000 deaths; in 1949, it caused only 161 deaths. Deaths from diarrhea enteritis and dysentery, also filth-____________________