- Email: [email protected]
Drinking water quality
156
Information section--Fd Chem. Toxic. Vol. 31, No. 2
from heart disease among those under 65. This is regarded as attainable in view of an 18% reduction achieved in only 4 yr (1986-90). The Chief Medical Officer has commissioned a group of nutritional experts under the chairmanship of Professor Philip James of the Rowett Institute to make dietary recommendations and describe the detailed changes that will be needed, following which nutritional targets for Scotland will be set. The help of farming, food processing and retailing organizations in improving the diet is also being sought. [Scotland's
Health: A Challenge to us All. A policy statement. The Scottish Office. HMSO, Edinburgh, 1992, pp. 45. £19.50.] A summary version of 'The Health of the Nation' is available from the Doll (tel. 071-972 4466/7) and a free booklet for the general public entitled 'The Health of the Nation and You' is available from BAPS, Health Publications Unit, Storage and Distribution Centre, Heywood Stores, Manchester Road, Heywood, Lancs. OLI02PZ (freephone 0800-444 250).
ANIMAL FEEDINGSTUFFS The Expert Group on Animal Feedingstuffs has been reviewing current legislation on animal feeds (MAFF News Release 60/91, 21 February 1991) and has now reported its findings. One major recommendation is that an independent Animal Feedingstuffs Advisory Committee should be established to take an overview of all feedingstuffs issues in relation to human and animal health. The Committee should co-ordinate and advise on policy and legislative measures and EC proposals. It should also review and advise on the nutritional characteristics and safety of feed ingredients; the safety, quality and efficacy of feed additives; undesirable substances in feedingstuffs; and recycling of own-species material. If there is a delay in EC consideration of silage agents, probiotics and enzymes, (currently subject in the UK only to the general provisions of the Agriculture Act), the Committee should begin to evaluate those available in the UK. In addition, it should consider any new class of additives, not covered by EC controls, that appears on the UK market, and there should be a statutory requirement for manufacturers to notify such additives. The procedure for setting national tolerances for feed additives not covered by EC provisions, or for which the EC has set only minimum tolerances, should be formalized. The Expert Group also recommends that fish farmers who use medicinal additives, and on-farm mixers using medicinal additives and intermediate medicated feedingstuffs, should be registered with the Royal Pharmaceutical Society of Great Britain, or in DRINKING
Northern Ireland with the Department Of Agriculture. It should be made clear in the regulations and in guidance to the industry that veterinary medicines can be used in feedingstuffs only in accordance with the product licence. As sulphonamide residues continue to be found in pig kidneys, despite considerable efforts to reduce levels by all concerned (Veterinary Residues in Animal Products 1986 to 1990. The thirty-third report of Steering Group on Chemical Aspects of Food Surveillance. M A F F Food Surveillance Paper No. 33. HMSO, London, 1992, pp. 82), the licensing for feed use of drugs that require long withdrawal periods should be carefully considered. Monitoring of antibiotic resistance in Salmonella should be continued, and routine monitoring of such resistance in human E. coli should be established. Not only should antibiotics giving cross-resistance to those used in human medicine not be used as growth promoters, but their prophylactic use in animals should also be reconsidered. A further recommendation is that the UK should continue its efforts to secure the advice of independent experts in the EC system for approval of medicinal products. The Veterinary Products Committee (VPC) agenda and proceedings should be made more freely available, and criteria for classification of veterinary medicines for feed use as pharmacy and merchants lists products, or as prescription only medicines, should be published as part of the regular reports of VPC activities. [The Report of the Expert Group on Animal Feedingstuffs. HMSO, London, 1992, pp. vi + 102. £15.00.]
WATER QUALITY
The quality of drinking water in England and Wales has apparently deteriorated over the past year, according to the annual report of the Drinking Water Inspectorate. Of some 3.57 million analyses by water companies, 44,973 (1.3%) did not comply with EC regulations, as compared with 32,474 (1.0%) in 1990. However, most of the increase was ascribed to changes in the sampling frequencies and monitoring strategies for individual pesticides. 34 pesticides were
detected above the EC limit of 0.1 #g/litre, as compared with 31 in 1990, and 2.8% (23,159) of determinations for individual pesticides exceeded the limit, as compared with 2.1% (11,269) in 1990 (Drinking Water 1990. A report by the Chief Inspector Drinking Water Inspectorate. Department of the Environment and Welsh Office. HMSO, London, 1991. pp. 194). In the Thames Water area (which was the subject of controversy last year), the EC limits for
Information seetion--Fd Chem. Toxic. Vol. 31, No. 2 atrazine, isoproturon, simazine, diuron, chlortoluron and total pesticides were exceeded in 72.1, 24.1, 23.7, 21.0, 0.6 and 20.8% of determinations, respectively. All companies that have confirmed the continuing presence of pesticides in breach of the regulations are said either to have improvement programmes in place, or to be preparing them in response to enforcement action. Increases were also evident during 1991 in the proportion of analyses exceeding prescribed levels for nitrite (4.8%), lead (3.0%) and polycyclic aromatic hydrocarbons (2.0%) (as compared with 3.7%, 2.7% and 1.4%, respectively, in 1990). Increased sampling frequencies in areas where contraventions were previously detected were again thought to be responsible for the apparent increases, except in the case of nitrite (where the reason was unidentified). Detection of aluminium, iron and manganese decreased, probably reflecting the improvement of treatment works and the refurbishment of distribution systems. In the case of trihalomethanes there was a decrease in the number of determinations above 100#g/litre, but an increase in the number of zones not meeting the standard. A review during 1991 of programmes to deal with breaches of the standards for parameters other than pesticides suggested that most remained appropriate, but the Inspectorate is considering what action is needed in respect of those which were not. During 1991 the Water Research Centre (WRC) completed a study of potential mutagens formed during chlorination and their toxicity in animals, and the results were evaluated by the Committee on Mutagenicity, who concluded in October 1991 that treated drinking water presented little risk in this respect. The Committee on Carcinogenicity likewise concluded in April 1992 that there was no sound
157
evidence that chlorinated water increased the risk of cancer, and replacement of chlorination by other disinfectants was unnecessary. (A CoM/CoC report will be published in due course.) However, because it is considered prudent to reduce the concentration of disinfection by-products if this can be done without prejudicing microbiological quality, the WRC is studying the formation of halogenated acetic acids during chlorine disinfection, and of ozone byproducts such as bromate. During 1991 the WRC completed a review of the potential for release of contaminants into treated water from distribution system materials (including pipe and tank linings, and reaction products of chlorine with plastic pipes), and the British Geological Survey produced a report on the concentration and distribution of trace elements in British groundwater. Particulate lead in drinking water was found to be relatively uncommon and associated with elevated concentrations of iron and organic matter, control of which reduced its incidence, but it was not generally decreased by treatment to reduce plumbosolvency, and scouring pipes with carbon monoxide was of only transient benefit. Other subjects still under investigation include pesticide release into water, and the economics of restricting use in certain catchment areas; the toxicity in animals of microcystin LR and other algal toxins; methods of reducing the leaching of polycyclic aromatic hydrocarbons from coal tar linings of water mains; and the effectiveness of the costly monitoring programme required by EC regulations. [Drinking Water 1991. A report by the Chief Inspector, Drinking Water Inspectorate. Department of the Environment and Welsh Office. HMSO, London, 1992, pp. xiii + 272. £25.00.]
ABSTRACTS FROM THE LITERATURE
Cholesterol and heart disease
Allergy in infimey
A recent multistudy analysis published in the medical press suggested the commonly held belief that lowering cholesterol prevents coronary heart disease may have been strongly influenced by the citation of only supportive trials. The Swedish investigator compared the frequency of citation with the outcome of all identified controlled cholesterol lowering trials. The 14 trials considered by their directors to be supportive of the contention were cited almost six times more often than those (10) that were not. An overall statistical analysis of all the studies showed no effect of treatment. It was concluded that "lowering serum cholesterol concentration does not reduce mortality and is unlikely to prevent coronary heart disease" and "authors of papers on preventing coronary heart disease by lowering blood cholesterol values tend to cite only trials with positive results" (Ravnskov, British Medical Journal 1992, 305, 15).
A group of UK investigators has examined whether avoidance of food and inhaled allergens in infancy protects against development of allergic disorders in later life. The mothers of 58 breast-fed infants from families with a history of sensitivity consumed an allergen-restricted diet (dairy products, egg, fish or nuts) and avoided feeding their infants any of these foods, or wheat, soya or orange. When compared at 12 months of age with 62 control infants with the same type of family history but who received a normal diet, allergic symptoms were less frequent in those receiving the restricted diet. Allergy developed in 25 (40%) of the control group, but only 8 (13%) of the group with the restricted diet (Arshad et al., Lancet 1992, 339, 493).
Kelp supplements Abnormal bleeding with widespread bruising and formation of small haemorrhagic patches under the
Information section--Fd Chem. Toxic. Vol. 31, No. 2
from heart disease among those under 65. This is regarded as attainable in view of an 18% reduction achieved in only 4 yr (1986-90). The Chief Medical Officer has commissioned a group of nutritional experts under the chairmanship of Professor Philip James of the Rowett Institute to make dietary recommendations and describe the detailed changes that will be needed, following which nutritional targets for Scotland will be set. The help of farming, food processing and retailing organizations in improving the diet is also being sought. [Scotland's
Health: A Challenge to us All. A policy statement. The Scottish Office. HMSO, Edinburgh, 1992, pp. 45. £19.50.] A summary version of 'The Health of the Nation' is available from the Doll (tel. 071-972 4466/7) and a free booklet for the general public entitled 'The Health of the Nation and You' is available from BAPS, Health Publications Unit, Storage and Distribution Centre, Heywood Stores, Manchester Road, Heywood, Lancs. OLI02PZ (freephone 0800-444 250).
ANIMAL FEEDINGSTUFFS The Expert Group on Animal Feedingstuffs has been reviewing current legislation on animal feeds (MAFF News Release 60/91, 21 February 1991) and has now reported its findings. One major recommendation is that an independent Animal Feedingstuffs Advisory Committee should be established to take an overview of all feedingstuffs issues in relation to human and animal health. The Committee should co-ordinate and advise on policy and legislative measures and EC proposals. It should also review and advise on the nutritional characteristics and safety of feed ingredients; the safety, quality and efficacy of feed additives; undesirable substances in feedingstuffs; and recycling of own-species material. If there is a delay in EC consideration of silage agents, probiotics and enzymes, (currently subject in the UK only to the general provisions of the Agriculture Act), the Committee should begin to evaluate those available in the UK. In addition, it should consider any new class of additives, not covered by EC controls, that appears on the UK market, and there should be a statutory requirement for manufacturers to notify such additives. The procedure for setting national tolerances for feed additives not covered by EC provisions, or for which the EC has set only minimum tolerances, should be formalized. The Expert Group also recommends that fish farmers who use medicinal additives, and on-farm mixers using medicinal additives and intermediate medicated feedingstuffs, should be registered with the Royal Pharmaceutical Society of Great Britain, or in DRINKING
Northern Ireland with the Department Of Agriculture. It should be made clear in the regulations and in guidance to the industry that veterinary medicines can be used in feedingstuffs only in accordance with the product licence. As sulphonamide residues continue to be found in pig kidneys, despite considerable efforts to reduce levels by all concerned (Veterinary Residues in Animal Products 1986 to 1990. The thirty-third report of Steering Group on Chemical Aspects of Food Surveillance. M A F F Food Surveillance Paper No. 33. HMSO, London, 1992, pp. 82), the licensing for feed use of drugs that require long withdrawal periods should be carefully considered. Monitoring of antibiotic resistance in Salmonella should be continued, and routine monitoring of such resistance in human E. coli should be established. Not only should antibiotics giving cross-resistance to those used in human medicine not be used as growth promoters, but their prophylactic use in animals should also be reconsidered. A further recommendation is that the UK should continue its efforts to secure the advice of independent experts in the EC system for approval of medicinal products. The Veterinary Products Committee (VPC) agenda and proceedings should be made more freely available, and criteria for classification of veterinary medicines for feed use as pharmacy and merchants lists products, or as prescription only medicines, should be published as part of the regular reports of VPC activities. [The Report of the Expert Group on Animal Feedingstuffs. HMSO, London, 1992, pp. vi + 102. £15.00.]
WATER QUALITY
The quality of drinking water in England and Wales has apparently deteriorated over the past year, according to the annual report of the Drinking Water Inspectorate. Of some 3.57 million analyses by water companies, 44,973 (1.3%) did not comply with EC regulations, as compared with 32,474 (1.0%) in 1990. However, most of the increase was ascribed to changes in the sampling frequencies and monitoring strategies for individual pesticides. 34 pesticides were
detected above the EC limit of 0.1 #g/litre, as compared with 31 in 1990, and 2.8% (23,159) of determinations for individual pesticides exceeded the limit, as compared with 2.1% (11,269) in 1990 (Drinking Water 1990. A report by the Chief Inspector Drinking Water Inspectorate. Department of the Environment and Welsh Office. HMSO, London, 1991. pp. 194). In the Thames Water area (which was the subject of controversy last year), the EC limits for
Information seetion--Fd Chem. Toxic. Vol. 31, No. 2 atrazine, isoproturon, simazine, diuron, chlortoluron and total pesticides were exceeded in 72.1, 24.1, 23.7, 21.0, 0.6 and 20.8% of determinations, respectively. All companies that have confirmed the continuing presence of pesticides in breach of the regulations are said either to have improvement programmes in place, or to be preparing them in response to enforcement action. Increases were also evident during 1991 in the proportion of analyses exceeding prescribed levels for nitrite (4.8%), lead (3.0%) and polycyclic aromatic hydrocarbons (2.0%) (as compared with 3.7%, 2.7% and 1.4%, respectively, in 1990). Increased sampling frequencies in areas where contraventions were previously detected were again thought to be responsible for the apparent increases, except in the case of nitrite (where the reason was unidentified). Detection of aluminium, iron and manganese decreased, probably reflecting the improvement of treatment works and the refurbishment of distribution systems. In the case of trihalomethanes there was a decrease in the number of determinations above 100#g/litre, but an increase in the number of zones not meeting the standard. A review during 1991 of programmes to deal with breaches of the standards for parameters other than pesticides suggested that most remained appropriate, but the Inspectorate is considering what action is needed in respect of those which were not. During 1991 the Water Research Centre (WRC) completed a study of potential mutagens formed during chlorination and their toxicity in animals, and the results were evaluated by the Committee on Mutagenicity, who concluded in October 1991 that treated drinking water presented little risk in this respect. The Committee on Carcinogenicity likewise concluded in April 1992 that there was no sound
157
evidence that chlorinated water increased the risk of cancer, and replacement of chlorination by other disinfectants was unnecessary. (A CoM/CoC report will be published in due course.) However, because it is considered prudent to reduce the concentration of disinfection by-products if this can be done without prejudicing microbiological quality, the WRC is studying the formation of halogenated acetic acids during chlorine disinfection, and of ozone byproducts such as bromate. During 1991 the WRC completed a review of the potential for release of contaminants into treated water from distribution system materials (including pipe and tank linings, and reaction products of chlorine with plastic pipes), and the British Geological Survey produced a report on the concentration and distribution of trace elements in British groundwater. Particulate lead in drinking water was found to be relatively uncommon and associated with elevated concentrations of iron and organic matter, control of which reduced its incidence, but it was not generally decreased by treatment to reduce plumbosolvency, and scouring pipes with carbon monoxide was of only transient benefit. Other subjects still under investigation include pesticide release into water, and the economics of restricting use in certain catchment areas; the toxicity in animals of microcystin LR and other algal toxins; methods of reducing the leaching of polycyclic aromatic hydrocarbons from coal tar linings of water mains; and the effectiveness of the costly monitoring programme required by EC regulations. [Drinking Water 1991. A report by the Chief Inspector, Drinking Water Inspectorate. Department of the Environment and Welsh Office. HMSO, London, 1992, pp. xiii + 272. £25.00.]
ABSTRACTS FROM THE LITERATURE
Cholesterol and heart disease
Allergy in infimey
A recent multistudy analysis published in the medical press suggested the commonly held belief that lowering cholesterol prevents coronary heart disease may have been strongly influenced by the citation of only supportive trials. The Swedish investigator compared the frequency of citation with the outcome of all identified controlled cholesterol lowering trials. The 14 trials considered by their directors to be supportive of the contention were cited almost six times more often than those (10) that were not. An overall statistical analysis of all the studies showed no effect of treatment. It was concluded that "lowering serum cholesterol concentration does not reduce mortality and is unlikely to prevent coronary heart disease" and "authors of papers on preventing coronary heart disease by lowering blood cholesterol values tend to cite only trials with positive results" (Ravnskov, British Medical Journal 1992, 305, 15).
A group of UK investigators has examined whether avoidance of food and inhaled allergens in infancy protects against development of allergic disorders in later life. The mothers of 58 breast-fed infants from families with a history of sensitivity consumed an allergen-restricted diet (dairy products, egg, fish or nuts) and avoided feeding their infants any of these foods, or wheat, soya or orange. When compared at 12 months of age with 62 control infants with the same type of family history but who received a normal diet, allergic symptoms were less frequent in those receiving the restricted diet. Allergy developed in 25 (40%) of the control group, but only 8 (13%) of the group with the restricted diet (Arshad et al., Lancet 1992, 339, 493).
Kelp supplements Abnormal bleeding with widespread bruising and formation of small haemorrhagic patches under the