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Biomedical subjects

A M Farmer

Publications and source records attributed to A M Farmer.

8 recordsLinked to original sources
PubMed2001

Reducing phosphate discharges: the role of the 1991 EC urban wastewater treatment directive.

This paper reviews the status of implementation of the 1991 EC urban wastewater treatment Directive in relation to its requirements for phosphate removal from wastewater discharges. Transposition of the Directive is satisfactory in most Member States as is implementation of requirements regarding collection and secondary treatment of sewage, with the notable exceptions of Belgium and Italy. A range of approaches has been adopted for the designation of sensitive areas under the Directive and designation is still not complete. It is likely that most Member States will have met the treatment requirements for sensitive areas by the end of 1998. Exceptions will include France and Spain (where implementation will be incomplete), the UK (which designated more sensitive areas in 1998 and will meet requirements for these at a later date) and Greece and Italy (for which sensitive area designation is lacking or uncertain). The Commission has indicated that it will examine compliance for both designation and treatment closely. This may place further pressure on Member States to designate further sensitive areas. It is estimated that currently in ten EU Member States, containing 90% of the EU population, about 375,000 tonnes of phosphorus are produced in domestic wastewater each year. In 1994 39-45% of this was removed in wastewater treatment works.

Cities↗
PubMed2000

Concentrations of cadmium, lead and zinc in livestock feed and organs around a metal production centre in eastern Kazakhstan.

This paper presents results of analysis of animal feed and meat (cattle, horse and sheep) products from a metal processing region (Oskemen) in east Kazakhstan. Samples were collected from a range of districts of differing distances from the main source of anthropogenic pollution and with differing underlying metal-containing geologies. Analyses for cadmium, lead and zinc revealed high concentrations in many feed and meat samples. Horse (an important food animal) samples had higher levels of contamination than cattle, which were higher than sheep. For example, mean cadmium concentrations in horse kidneys in one district were found to be 128 mg/kg and lead concentrations for liver 2.2 mg/kg. These, and other, results are generally higher than reported in many other studies in contaminated regions of eastern Europe and they can exceed State Maximal Allowed Concentrations by many times. As such levels of contamination pose a significant potential risk to human health, these results have formed the basis for subsequent research on levels of metal contamination in human tissues from affected populations.

Animal Feed↗
PubMed1993

The effects of dust on vegetation--a review.

An increase in quarrying, open-cast mining and road traffic suggest that dust deposition onto vegetation may be increasing. This review describes the physical and chemical characters of a range of dust types. The effects of dust on crops, grasslands, heathlands, trees and woodlands, arctic bryophyte and lichen communities are identified. Dust may affect photosynthesis, respiration, transpiration and allow the penetration of phytotoxic gaseous pollutants. Visible injury symptoms may occur and generally there is decreased productivity. Most of the plant communities are affected by dust deposition so that community structure is altered. Epiphytic lichen and Sphagnum dominated communities are the most sensitive of those studied. However, there have been very few detailed studies on natural and semi-natural systems and some dust types are also very understudied. Recommendations for future research are made in order to overcome this deficiency.

Journal Article↗
PubMed1990

Epiphyte recolonization of oaks along a gradient of air pollution in South-East England, 1979-1990.

The abundances of epiphytes on free-standing oaks (Quercus robur) along a transect extending approximately 70 km SSW from Central London were redetermined annually from 1979 to 1990. During this period SO(2) levels in inner London fell to between one-quarter and one-seventh of levels occurring in the 1960s. The sample trees were also scored annually using Hawksworth and Rose's (1970) scale for predicting SO(2) levels from the epiphytes present. Little evidence was obtained for epiphyte recolinization of oaks at sites within the built-up area. At Epsom Common, on the urban fringe, cover of the pollution-tolerant lichen Lecanora conizaeoides fell, and in the inner suburbs, at Putney Heath, L. conizaeoides and Lepraria incana increased, while the alga Desmococcus viridis declined at this site. These changes might be due to a contraction inwards of zones of peak abundance of L. conizaeoides and D. viridis with decreasing SO(2) levels. However, it is also possible that the changes at Putney Heath resulted from scrub clearance activities and alteration to the microclimate. The cover of the moderately SO(2) tolerant foliose lichen Hypogymnia physodes remained low and static at Putney Heath during the 12-year period. Possible reasons for the poor recolinization of London's oaks by epiphytes are discussed. Particular emphasis is given to the highly acidic bark of oak in the London area (pH2.9-4.0) in comparison with other tree species and with oaks in unpolluted regions.

Journal Article↗
PubMed1990

The effects of lake acidification on aquatic macrophytes--a review.

Acidification of lakes results in a number of chemical, physical and biological changes. This review initially outlines the major floristic changes that occur in acidifying and limed lakes. The different types of evidence (historical comparisons, inter-lake comparisons and palaeoecological studies) are considered. These studies emphasise the replacement of calcicole species and others such as the isoetids with Juncus bulbosus and Sphagnun spp. in acidifying lakes. The review then discusses the way in which the various alterations in lake conditions affect the physiology of the macrophytes, particularly with changes in the availability of carbon, a change from nitrate to ammonium as a nitrogen source and the effects of an alteration in the Lake light climate. The population biology, community ecology and ecosystem functioning of macrophytes are discussed, especially where competitive processes may seem more important in determining community change than physiological processes. Particular consideration is paid to the types of evidence of floristic change that are useful and the importance of undertaking experimental studies at the correct scale to determine which factors may be causally related to the floristic evidence.

Journal Article↗
PubMed1980

Epidemiology of Corynebacterium equi in horses.

Using a selective medium, the epidemiology of Corynebacterium equi in horses was studied. Twelve horse studs in different geographical locations were investigated. In addition, a group of horses was monitored over a period of time to determine whether faecal carriage of C equi is constant or intermittent. It was found that C equi could be recovered from every property tested and from all horse breeds. The organism was found in mares, stallions, yearlings and two year olds, and foals aged from 10 days to several months. It appears that C equi is widespread and that its occurrence is not related to any particular geographical location nor to a limited number of properties within a given area. Furthermore, it seems likely that C equi is part of the normal equine faecal flora. The results challenge the notion that C equi is primarily soil associated and do not support the concept that there are infected and non-infected areas.

Animals↗
PubMed1979

Selective medium for Corynebacterium equi isolation.

The development of a selective medium for the isolation of Corynebacterium equi is described. The medium has been used to examine fecal samples from 127 horses of which 90 have been found to carry the organism.

Animals↗