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Joint survey of pesticide residues in foodstuffs sold in England and Wales, 1 August 1967–31 July 1968 (Second Year)
400
REVIEWS OF RECENT PUBLICATIONS
liver contained appreciable levels, with mean mercury levels of 0.04 and 0.02 ppm respectively. In canned tuna, levels of 0.12-0.3 ppm (mean 0.18 ppm) were detected, but in other canned fish mean amounts were between 0.01 and 0.04 ppm. In fresh fish, levels increased with increasing proximity to the coast; those caught in distant waters (which account for 64 ~o of total fish landings in England and Wales) contained an average, weighted according to the proportion of landings from each area, of 0.06 ppm mercury, while in fish from middledistance waters and those from areas up to 25 miles off the coast, the weighted mean concentrations were 0.11 and 0.21 ppm respectively. Fish from parts of the Thames Estuary and the eastern Irish Sea were found to contain the highest concentrations (in the region of 0.5 ppm) but such fish represent well below 1% of the total UK landings. Shellfish from coastal areas also contained high levels, the weighted average concentration being 0.16 ppm overall, with as much as 0.32 ppm in samples from the Irish Sea. However, since shellfish account for only 5% of total landings, these levels did not affect the average mercury concentration of all fish and shellfish, estimated as 0-08 ppm. Freshwater salmon and trout contained mean levels of 0.08 and 0.16 ppm respectively, and in pike (fortunately of negligible importance in the British diet) a mean concentration of 0.47 ppm was recorded. More than 90~o of the total mercury in fish, and 40-90% of that in shellfish, was present as methylmercury. When these results were correlated with those obtained from the Total Diet Study it was calculated that the daily intake of mercury from food by the average consumer does not exceed 10/zg and is probably in the region of 7-8/zg. Of this about 2/~g is contributed by fish and shellfish, the per capita average consumption of which is ortly about 24 g/day. It was concluded that the only sections of the community which might consistently ingest well above average amounts of mercury were those consuming large quantities either of fish from certain coastal areas or of canned tuna. A pilot survey of seven such persons revealed mercury concentrations in whole blood 2-6 times greater than in control subjects, but there was no clear-cut difference as regards levels in hair. A two-page appendix on the health implications of methylmercury ingestion discusses the value of such a study but does not comment specifically on these findings, remarking only that the relationship between the body burden of mercury and clinically evident poisoning cannot be estimated with any certainty. Attention is also drawn to the absence of long-term studies which would permit an estimation of an acceptable daily intake of mercury for man. The report has been submitted to the Food Additives and Contaminants Committee and the Pharmacology Sub-Cormnittee, who have recommended that the monitoring programme for mercury need continue only in a much reduced form. The results of the survey for lead and cadmium will form the subject of further reports.
Joint Survey of Pesticide Residues in Foodstuffs Sold in England and Wales, 1 August 1967-31 July 1968 (Second Year). County Councils Association, Association of Municipal Corporations, Urban District Councils Association and Association of Public Analysts. The Association of Public Analysts, London, 1971. pp. 38. £1.10. This report presents the findings obtained in the second year of the nationwide survey of pesticide residues in foodstuffs begun during 1966. The report of the first year of the survey was issued in 1969 (Joint Survey of Pesticide Residues in Foodstuffs Sold in England and Wales,
1st August 1966-31st July 1967). Samples of home-produced or imported bread, infant foods, meat, poultry, fruit, vege-
REVIEWS OF RECENT PUBLICATIONS
401
tables, dairy products and beverages were examined for residues of organochlorine pesticides (BHC, aldrin, dieldrin, endrin, DDT, DDE, TDE and total DDT types), organophosphorus pesticides, arsenic, lead and mercury. The report notes the absence of any major differences between the results obtained in the 2 years; the second-year findings again showed no evidence of gross contamination and none of the results obtained were considered to warrant urgent remedial action. A slight increase in the prevalence of organochlorine residues was not considered significant. Some 2163 samples were examined fgr organochiorine residues and again lard proved to be the most heavily contaminated foodstuff. Home-produced and imported products showed similar residue patterns. A decline is to be expected in the organochlorine residues in home-produced dairy products and fruit following the 1969 restrictions on the use of organochlorine pesticides. Estimations of the total dietary intake of organochlorine pesticides from the figures obtained in this study indicate that only dieldrin slightly exceeded the FAO/WHO acceptable daily intake. Only 11 of the 2163 samples examined gave a positive response in the Drosophila screening test for organophosphorus residues, a reduction on the previous year's incidence. Chemical analysis revealed levels of 60-1370 ppb (b = 109) in various foods. Of 173 samples examined for lead and arsenic, only three contained levels of arsenic in excess of the permitted limit and no excessive lead contamination was found, but the traces of these elements found in other foods suggest the need for continuing vigilance for arsenic and lead residues. Mercury residues were present in significant amounts in only two out of 228 samples examined. The report also refers to relatively high levels of pentachloronitrobenzene found in lettuce and recommends that future surveys should consider both this compound and thiocarbamates, high residues of which in other crops have been reported elsewhere.
REVIEWS OF RECENT PUBLICATIONS
liver contained appreciable levels, with mean mercury levels of 0.04 and 0.02 ppm respectively. In canned tuna, levels of 0.12-0.3 ppm (mean 0.18 ppm) were detected, but in other canned fish mean amounts were between 0.01 and 0.04 ppm. In fresh fish, levels increased with increasing proximity to the coast; those caught in distant waters (which account for 64 ~o of total fish landings in England and Wales) contained an average, weighted according to the proportion of landings from each area, of 0.06 ppm mercury, while in fish from middledistance waters and those from areas up to 25 miles off the coast, the weighted mean concentrations were 0.11 and 0.21 ppm respectively. Fish from parts of the Thames Estuary and the eastern Irish Sea were found to contain the highest concentrations (in the region of 0.5 ppm) but such fish represent well below 1% of the total UK landings. Shellfish from coastal areas also contained high levels, the weighted average concentration being 0.16 ppm overall, with as much as 0.32 ppm in samples from the Irish Sea. However, since shellfish account for only 5% of total landings, these levels did not affect the average mercury concentration of all fish and shellfish, estimated as 0-08 ppm. Freshwater salmon and trout contained mean levels of 0.08 and 0.16 ppm respectively, and in pike (fortunately of negligible importance in the British diet) a mean concentration of 0.47 ppm was recorded. More than 90~o of the total mercury in fish, and 40-90% of that in shellfish, was present as methylmercury. When these results were correlated with those obtained from the Total Diet Study it was calculated that the daily intake of mercury from food by the average consumer does not exceed 10/zg and is probably in the region of 7-8/zg. Of this about 2/~g is contributed by fish and shellfish, the per capita average consumption of which is ortly about 24 g/day. It was concluded that the only sections of the community which might consistently ingest well above average amounts of mercury were those consuming large quantities either of fish from certain coastal areas or of canned tuna. A pilot survey of seven such persons revealed mercury concentrations in whole blood 2-6 times greater than in control subjects, but there was no clear-cut difference as regards levels in hair. A two-page appendix on the health implications of methylmercury ingestion discusses the value of such a study but does not comment specifically on these findings, remarking only that the relationship between the body burden of mercury and clinically evident poisoning cannot be estimated with any certainty. Attention is also drawn to the absence of long-term studies which would permit an estimation of an acceptable daily intake of mercury for man. The report has been submitted to the Food Additives and Contaminants Committee and the Pharmacology Sub-Cormnittee, who have recommended that the monitoring programme for mercury need continue only in a much reduced form. The results of the survey for lead and cadmium will form the subject of further reports.
Joint Survey of Pesticide Residues in Foodstuffs Sold in England and Wales, 1 August 1967-31 July 1968 (Second Year). County Councils Association, Association of Municipal Corporations, Urban District Councils Association and Association of Public Analysts. The Association of Public Analysts, London, 1971. pp. 38. £1.10. This report presents the findings obtained in the second year of the nationwide survey of pesticide residues in foodstuffs begun during 1966. The report of the first year of the survey was issued in 1969 (Joint Survey of Pesticide Residues in Foodstuffs Sold in England and Wales,
1st August 1966-31st July 1967). Samples of home-produced or imported bread, infant foods, meat, poultry, fruit, vege-
REVIEWS OF RECENT PUBLICATIONS
401
tables, dairy products and beverages were examined for residues of organochlorine pesticides (BHC, aldrin, dieldrin, endrin, DDT, DDE, TDE and total DDT types), organophosphorus pesticides, arsenic, lead and mercury. The report notes the absence of any major differences between the results obtained in the 2 years; the second-year findings again showed no evidence of gross contamination and none of the results obtained were considered to warrant urgent remedial action. A slight increase in the prevalence of organochlorine residues was not considered significant. Some 2163 samples were examined fgr organochiorine residues and again lard proved to be the most heavily contaminated foodstuff. Home-produced and imported products showed similar residue patterns. A decline is to be expected in the organochlorine residues in home-produced dairy products and fruit following the 1969 restrictions on the use of organochlorine pesticides. Estimations of the total dietary intake of organochlorine pesticides from the figures obtained in this study indicate that only dieldrin slightly exceeded the FAO/WHO acceptable daily intake. Only 11 of the 2163 samples examined gave a positive response in the Drosophila screening test for organophosphorus residues, a reduction on the previous year's incidence. Chemical analysis revealed levels of 60-1370 ppb (b = 109) in various foods. Of 173 samples examined for lead and arsenic, only three contained levels of arsenic in excess of the permitted limit and no excessive lead contamination was found, but the traces of these elements found in other foods suggest the need for continuing vigilance for arsenic and lead residues. Mercury residues were present in significant amounts in only two out of 228 samples examined. The report also refers to relatively high levels of pentachloronitrobenzene found in lettuce and recommends that future surveys should consider both this compound and thiocarbamates, high residues of which in other crops have been reported elsewhere.