The priorities of the Environmental Health Unit lie in areas related to contamination of the environment and the possible adverse effects of environmental pollutants on human health.

Pesticides:

Pesticides are considered priority pollutants in Palestine. There are about 400 officially registered pesticides in Israel, some of which are banned for use in industrialized countries due to their high toxicity, low biodegradability, and mutagenic or carcinogenic potential. In addition there are pesticides registered in Israel that have not been registered in countries of origin. A very serious situation exists with respect to pesticide use, due to the exceedingly large volumes used and the lack of information available, in Arabic, to farmers and others dealing with pesticides.

During the past few years, the CEOHS has documented the following in its various research and survey activities:

• Thirty seven percent of farm produce tested had pesticide residues about World Health Organization "acceptable"
• Pesticides are used at an average of 7kg/dunum (4 dunums = 1 acre) in open agriculture and 11kg/dunum in greenhouses.
• The total sales volume exceeds 1300 metric tons at a cost of over $15 million per-year in the West Bank alone, making this region one of the world's heaviest users of pesticides per area under cultivation.
• Exposure of farmers and their families to pesticides is serious and, for those using organophosphate insecticides we have documented that it is playing havoc with aceytlcholinesterase levels in their bodies.
• A survey of knowledge, attitudes and practices on the subject of pesticide use indicates that farmers are not receiving extension services form community or governmental agencies, know very little about pesticides, believe that they are immune to their negative health effects, do not wear protective clothing or wash or change their clothes after spraying, and have not the vaguest idea of actual or recommended doses.

As a result of this appalling situation, in 1989 CEOHS embarked on a program on the "Safe Use of Pesticides" aimed at farmers and others handling them. The program is currently running in various parts of Palestine. To assure farmers that the problems that they are facing with pests are a result of pesticide resistance and not just adulteration of pesticides, cases of which have occurred, the Center is performing quality control studies on pesticides. (See the section below on the Occupational Health Unit for more details about this program).

In 1985 CEOHS introduced IPM as an integral part of its Safe Use of Pesticides program. Such training and educational programs include background information on pesticides and their mode of action, pests applicator training and dosing, first aid and IPM.

Water and Wastewater:

Since 1982, CEOHS has been involved in water monitoring. Monitoring of long term changes in the quality of Palestinian aquifers is an important priority at the Center. Research on water quality and health is one of the bulwarks of its activities. CEOHS has contracts with some water distribution authorities and municipalities to perform routine biological and chemical water quality monitoring. We have extended our water analysis to include monitoring of pesticide and othetoxic residues especially after we have added a GC/MS to our laboratory. In 1982/83, we surveyed the chemical quality of rainwater cisterns in the villages surrounding Birzeit University.

We studied water quality in Gaza Strip focusing on fluoride content and the development of dental fluorosis. Fluorides are naturally present in the water of Gaza Strip and the combination of consuming water with a high fluoride content a public health problem as evidenced by a moderately high dental fluorsis index in the population of the Gaza Strip.

At the request of the Union of Physicians and Dentists we performed an extensive survey of fluoride levels in all drinking water wells in the West Bank as a prerequisite to the prescribing of supplementary dietary fluorides to reduce the incidence of dental carries. The results indicated a generally low level of fluorides. As a bonus, during this survey, we measured water conductivity tests to determine the degree of salinity in West Bank water supplies. We found salinity to be variable depending on region with the central and southern regions having the sweetest water.

In 1990, we signed a contract with the Jerusalem water Undertaking/Ramallah District to do a long term study of the quality of water in all their water resources and network. Their network is the largest in the West Bank and covers four metropolitan areas and 52 villages. CEOHS does biological and chemical monitoring of water drawn from 170 sampling stations. Thus far, we have found the water in this network to be of high quality. A long term water quality assessment program covering Gaza and the West Bank is currently under way.

In 1994, the Center has opened a branch of CEOHS in Gaza City to serve the Gaza Strip. This laboratory specializes in biological chemical monitoring of water quality. Co-sponsored by the Gaza Environmental Program, a Gaza NGO, the laboratory is located in Gaza City. CEOHS will remain the mother laboratory and will be responsible for scientific directorship of the Gaza laboratory. CEOHS will perform those tests for which the Gaza laboratory is currently equipped for.

CEOHS offers its services to a wide variety of organizations, including grassroots organizations, institutions and factories by determining the quality of water samples brought to it be they for domestic, agricultural or industrial use.

CEOHS is also involved in the optimal solid and liquid waste disposal methods for our area, taking into consideration cost effectiveness, protection of public health and the preservation of the environment. Our expertise is being utilized to evaluate sewage treatment projects.