Cattle as Biomonitors of Soil Arsenic, Copper, and Zinc Concentrations in Galicia (NW Spain) M. Lo ´pez Alonso, 1,2 J. L. Benedito, 1 M. Miranda, 1 C. Castillo, 1 J. Herna ´ndez, 1 R. F. Shore 2 1 Universidade de Santiago de Compostela, Departamento de Patoloxia Animal, Facultade de Veterinaria, 27002 Lugo, Spain 2 NERC Centre for Ecology and Hydrology, Monks Wood, Abbots Ripton, Huntingdon, Cambridgeshire, PE28 2LS, UK Received: 13 August 2001 / Accepted: 23 January 2002 Abstract. Determination of soil concentrations of trace and pollutant metals over large spatial areas requires laborious and expensive sampling effort. In this study, we examined the feasibility of using calves as biomonitors of soil semimetal and trace metal concentrations in Galicia (NW Spain), a region in which calves are predominantly reared on grass or locally grown forage. We determined the concentrations of arsenic, copper, and zinc in the liver, kidney, muscle, and blood of calves from across Galicia and related them to the metal concentrations in the soil from the areas in which the animals were reared. For each element, liver (but not usually kidney, muscle, or blood) concentrations were significantly elevated in animals from areas with higher soil concentrations. Liver ar- senic concentrations were only markedly greater in animals from areas with soil arsenic levels  20 mg/kg, and calves may not be sensitive enough biomonitors of background variation in soil levels, although they may be useful for monitoring anthro- pogenic arsenic contamination. Copper and zinc liver levels increased progressively with soil levels, and the pattern was especially marked for copper. The relatively unusual copper metabolism of cattle and other ruminants may make them particularly good biomonitors for environmental concentra- tions of this metal. Various animal species have been suggested as suitable bio- monitors of trace and pollutant metal levels in the terrestrial environment (MARC 1990; O’Brien et al. 1993). The use of such biomonitors has the advantage over analysis of soil, air, and water in that it provides a measure of exposure that is integrated spatially, temporally, and across media (Talmage and Walton 1991). Where human health is the primary concern, biomonitors should ideally be (1) widely distributed to allow cross-habitat comparisons but territorial and nonmigratory so that measured concentrations can be linked to source areas; (2) numerous and relatively large so that it is feasible to collect sufficient numbers of samples for chemical and other (such as histological) analysis; (3) near the top of a food chain so that any biomagnification is detected; (4) relatively long-lived and broadly similar to humans in their physiological and toxico- logical responses to contaminants if they are to be used to predict the likely effects of short-and long-term exposure (Holden 1973; Landres et al. 1988; O’Brien et al. 1993, Es- selink et al. 1995). It has been argued that animals in livestock production largely fulfill these criteria (Ronneau et al. 1983; Ronneau and Cara 1984; Morcombe et al. 1994; Petersson Grawe ´ et al. 1997), and, in rural areas, this is likely to be true if livestock are reared on grass or locally grown fodder. In addition, domestic animals have the advantage that they are an important source of food for humans and so provide a direct measure of pollutant transfer to humans (O’Brien et al. 1993). In Galicia (NW Spain), cattle are the most numerous of the different kinds of livestock and are fed predominantly on grass and locally grown fodder. Thus, cattle are the type of livestock most likely to prove good biomonitors of trace and contaminant metal concentrations in Galicia. The aim of this study was to investigate if the concentrations of metals and semimetals in the tissues of cattle were correlated with those in the soil in Galicia and to evaluate the feasibility of using cattle as bio- monitors of environmental metal/semimetal levels in this re- gion. Material and Methods Animal Sampling and Chemical Analysis During June–November 1996, tissues were taken from a stratified random sample of calves from all of the slaughterhouses in Galicia. This was done to ensure that the sample collected was representative of the whole region. Information on the age, precise origin, and husbandry history of the animals was obtained from farm documen- tation. Only animals reared for their entire lives on the same farm and fed predominantly local forage were sampled. In total, tissues were taken from 438 (male and female) calves aged between 6 and 10 months. All were healthy at the time of slaughter. Metal concentrations were determined in (1) the liver and kidney, because they are key organs that accumulate relatively high concen- trations of certain elements; (2) muscle, because of its importance in foodstuffs; and (3) blood, because this allowed assessment of the use Correspondence to: M. Lo ´pez Alonso; email: mlalonso@lugo.usc.es Arch. Environ. Contam. Toxicol. 43, 103–108 (2002) DOI: 10.1007/s00244-002-1168-5 ARCHIVES OF Environmental Contamination and T oxicology © 2002 Springer-Verlag New York Inc.