Impact of effects of acid precipitation on toxicity of metals

Our plain-English summary of Impact of effects of acid precipitation on toxicity of metals, by G.F. Nordberg, R.A. Goyer, T.W. Clarkson (Environmental Health Perspectives, 1985).

The study

• Authors: G.F. Nordberg, R.A. Goyer, T.W. Clarkson
• Journal: Environmental Health Perspectives
• Published: 1985;63:169-80
• Type of article: Review
• Cited by: 34 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Acid precipitation may increase human exposure to several potentially toxic metals by increasing metal concentrations in major pathways to man, particularly food and water, and in some instances by enhancing the conversion of metal species to more toxic forms. Human exposures to methylmercury are almost entirely by way of consumption of fish and seafood. In some countries, intakes by this route may approach the levels that can give rise to adverse health effects for population groups with a high consumption of these food items. A possible increase in methylmercury concentrations in fish from lakes affected by acid precipitation may thus be of concern to selected population groups. Human exposures to lead reach levels that are near those associated with adverse health effects in certain sensitive segments of the general population in several countries. The possibility exists that increased exposures to lead may be caused by acid precipitation through a mobilization of lead from soils into crops. A route of exposure to lead that may possibly be influenced by acid precipitation is an increased deterioration of surface materials containing lead and a subsequent ingestion by small children. A similar situation with regard to uptake from food exists for cadmium (at least in some countries). Human metal exposures via drinking water may be increased by acid precipitation. Decreasing pH increases corrosiveness of water enhancing the mobilization of metal salts from soil; metallic compounds may be mobilized from minerals, which may eventually reach drinking water. Also, the dissolution of metals (Pb, Cd, Cu) from piping systems for drinking water by soft acidic waters of high corrosivity may increase metal concentrations in drinking water. Exposures have occasionally reached concentrations which are in the range where adverse health effects may be expected in otherwise healthy persons. Dissolution from piping systems can be prevented by neutralizing the water before distribution. Increased aluminum concentrations in water is a result mainly of the occurrence of Al in acidified natural waters and the use of Al chemicals in drinking water purification. If such water is used for dialysis in patients with chronic renal failure, it may give rise to cases of dialysis dementia and other disorders. A possible influence on health of persons with normal renal function (e.g., causing Alzheimer's disease) is uncertain and requires further investigation.(ABSTRACT TRUNCATED AT 400 WORDS)

In plain English

This 1985 article was a review, not a new study. The authors summarized published evidence on whether acid precipitation could increase human exposure to toxic metals. It dealt mainly with mercury (as methylmercury in fish), lead, cadmium and aluminum, with shorter sections on arsenic, selenium, copper and asbestos. For these four metals, they reviewed evidence on the doses linked to harmful effects and on how people are exposed. Asbestos appeared in only one brief passage. The authors wrote that asbestos-cement pipes had been used extensively for larger drinking water pipes, and that acidic water of high corrosivity distributed in such pipes may release asbestos fibers. They gave no fiber type, no measurements and no health findings for asbestos. Overall, the authors wrote that the ways acid precipitation might raise metal exposure do exist, but information allowing a quantitative estimate of their importance was almost entirely lacking. They named aluminum dose-response relationships as the most urgent research need. The authors concluded that the links between acid precipitation and human exposure to potentially toxic metals were, at best, only partially defined.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: review (summary of available evidence)
• Who was studied: No study population of its own. The authors reviewed published evidence on human exposure to metals, including from Sweden, the U.S., Scotland, Iraq and Japan.
• Exposure: Metals possibly mobilized by acid precipitation: methylmercury, lead, cadmium, aluminum, arsenic, selenium and copper. Asbestos fibers possibly released from asbestos-cement drinking water pipes by acidic, corrosive water. No asbestos fiber type is named.
• Main results:
  • The authors wrote that when acidic water of high corrosivity is distributed in asbestos-cement pipes, asbestos fibers may be released. No measurements or health data for asbestos were given.
  • Across the metals reviewed, the authors wrote that information allowing a quantitative estimate of the importance of increased exposure due to acid precipitation was almost entirely lacking.
  • In copper pipes, the review reported copper concentrations as high as 20 mg/L in water standing in pipes overnight.
  • The authors identified dose-response relationships for aluminum as the most urgent research need, because knowledge was very incomplete.
• The authors' conclusion: The authors concluded that, at that time, the relationships between acid precipitation and human exposure to potentially toxic metals were, at best, only partially defined.
• Limitations the authors state:
  • The authors stated that uncertainties in dose-response data and exposure data were considerable in several instances. This limited their ability to make a precise evaluation.

Topics

Medical terms in this study, explained in our Lexicon: Fluorescence In Situ Hybridization (FISH).

Related studies

• Metal interactions in carcinogenesis: enhancement, inhibition — G.F. Nordberg, O. Andersen (1981)
• The effects of acid precipitation runoff episodes on reservoir and tapwater quality in an Appalachian Mountain water supply — W.E. Sharpe, D.R. DeWalle (1990)
• Assessment of both environmental cytotoxicity and trace metal pollution using Populus simonii Carr. as a bioindicator — V. Sluchyk, I. Sluchyk, et al. (2014)
• Asbestos and metals as carcinogens — T. Norseth (1980)
• Additional histopathologic examination of the lungs from a 3-month inhalation toxicity study with multiwall carbon nanotubes in rats — S. Treumann, L. Ma-Hock, et al. (2013)
• Topsoil and urban dust pollution and toxicity in Taranto (southern Italy) industrial area and in a residential district — M. Trifuoggi, G. Pagano, et al. (2018)

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