Talk about toxic

Toxicology dominates headlines in the wake of natural disasters, terror events, new illnesses and bizarre side effects from drugs. But the most exciting part, say its practitioners, is that one never knows where an investigation will lead — a toxicologist's turf can be anywhere. Recent studies have traced deaths of Asian vultures to a veterinary drug, identified an inhalation route for the toxin that causes paralytic shellfish poisoning and tracked a rare cancer in rural Turkey to a volcanic building material.

G. PALMER/CORBIS

Toxicology considers the effects on organisms of exposure to chemicals, biological agents and radiation. Emphasis on human health extends the field's scope beyond science.

"It is at the interface of science and public policies that many, and often heated, political issues come into play," says William Greenlee, president and chief executive of CIIT Centers for Health Research in Research Triangle Park, North Carolina, a private, nonprofit institute.

Making it clear: Ellen Silbergeld is best known for explaining the work of the Environmental Defense Fund to the media.JOHNS HOPKINS SCHOOL OF PUBLIC HEALTH

Despite toxicology's diverse worksites, the field is cemented by shared problem-solving strategies and the common language of risk assessment. The links are summed up by Kenneth Ramos, director of the centre for genetics and molecular medicine at the University of Louisville Health Sciences Center in Kentucky. "What binds toxicologists together is focus on the study of toxic responses caused by chemical, physical or biological agents; the consequences of toxicity in biological systems; and measures to prevent or ameliorate the devastating personal and societal consequences of toxicities," he says.

Because toxicology is quite a new, interdisciplinary applied science, it can be approached by different career pathways. So numerous and eclectic are job opportunities that it isn't uncommon for a seasoned scientist to have spent time in academia, industry and government, and finish with private consulting.

Toxicology came into its own in the 1960s. "There was a big awakening about the environment and chemicals," recalls Jay Gandolfi, assistant dean of research and graduate studies in the College of Pharmacology at the University of Arizona in Tucson.

"There has been a real evolution in safety assessment from 40 years ago, when we used a 'dose 'em and count 'em' approach," says Linda Birnbaum, director of the experimental toxicology laboratory at the Environmental Protection Agency (EPA) in Research Triangle Park, North Carolina. "Now analyses are much more molecular, targeted and mechanistic."

A career in toxicology might take a scientist to a contaminated well, a crime scene, a courtroom, an analytical chemistry lab or a political hearing. At the Environment Agency in Britain, for example, some scientists pursue basic research at a national centre and others become field-based environment-protection officers or join a policy team. Requirements range from broad training in biology or chemistry to specific expertise, such as in environmental oestrogens.

The International Neurotoxicology Association divides career opportunities into regulatory, commercial, scientific and medical, says its president David Ray, leader of the MRC Applied Neurosciences Group at the University of Nottingham, UK. Regulatory neurotoxicologists work for national or international agencies. The commercial track includes the drug, bulk chemical and pesticide industries.

All nations face toxicological problems, says Ray, but priorities vary. "In most developed countries, concerns centre on evaluation of new products, relatively low-level toxicity and reduction of accidental exposures. In developing countries perspectives can be very different," he says, citing the use of pesticides in China and Malaysia for suicide. Countries may present specific challenges, he adds, such as the neurotoxin domoic acid, sometimes found in Canadian mussels.

Keeping a grip: William Greenlee warns of heated political issues.CIIT CENTERS FOR HEALTH RESEARCH

Even though you can now gain a PhD in toxicology, broad training is still valuable. A neuroscience degree can segue into neurotoxicology, or an immunology degree into immunotoxicology. Now a consultant, Skip Matthews of Hertford, North Carolina, merged a background in entomology and an interest in chemistry into a three-decade career in insecticide toxicology at the National Institute of Environmental Health Sciences (NIEHS) in Research Triangle Park.

Ellen Silbergeld, professor of environmental health sciences at the Johns Hopkins University Bloomberg School of Public Health in Baltimore, Maryland, recommends "a strong base in a relevant discipline, either in the biological or chemical sciences or in engineering work". After an undergraduate degree in history and a doctorate in engineering, Silbergeld learned toxicology as a postdoc. She is probably best known for her clear statements to the media, as senior consultant toxicologist for the Environmental Defense Fund in Washington DC.

Tips for toxicologists: you need on-your-feet problem-solving skills, says Barbara Beck; Rick Schnellmann finds that employers want people who can focus on a topic without losing sight of the big picture.ROBERT M. BAHN

Communication skills are vital when testifying. Forensic toxicologist Marc Pelletier, of the Centre of Forensic Sciences in Ontario, Canada, faces a courtroom nearly every week. He analyses body fluids for drugs, lectures to students and police officers, sees pathologists and coroners, and, like all toxicologists, writes many reports. After a doctorate in behavioural neuroscience, his training came mostly on the job. "All scientists are required to complete a comprehensive training programme specific to forensic toxicology at the centre, of approximately three years," says Pelletier.

Because most toxicologists work in groups, interpersonal skills are important. "Successful toxicologists are good observers and have learned management by following role models and then customizing the style to fit their situations," says Gandolfi.

Private consulting offers its own challenges, such as discussing risks with clients who aren't science-savvy. "A comfort level in working on a broad range of topics and good communication and on-your-feet problem-solving abilities are useful," says Barbara Beck, a toxicologist at Gradient in Cambridge, Massachusetts.

Combining scientific expertise with these talents is a tall order. Rick Schnellmann, chair of pharmaceutical sciences at the Medical University of South Carolina, Charleston, sums it up. "Employers want diverse laboratory skills, the ability to focus on a specific topic as well as looking at the big picture, excellent writing and communication skills, and motivation," he says.

You may want to try a taster before starting a doctorate. The Health Effects Institute in Boston, Massachusetts, a nonprofit organization informing government and industry about air pollution, seeks research assistants with degrees in toxicology, chemistry, epidemiology, biology, mechanical engineering or environmental science. The National Research Centre for Environmental Toxicology in Queensland, Australia, seeks students to help develop a system to remove arsenic from water supplies.

Because doctorates in toxicology are fairly new, many toxicologists entered "through the back door", says Jack Dean, retired president of US science and medical affairs at Sanofi–Aventis in Paris. Dean, whose graduate work was in molecular biology and biochemistry with a focus on immunology, also started the NIEHS immunotoxicology programme.

Pharmacology was the route for many, including James Bond, editor of Chemico-Biological Interactions in Durham, North Carolina. "Pharmacology deals with efficacy and toxicology deals with adverse effects," he says. "I became increasingly interested in how chemicals exerted their toxic effects on biological systems."

MaryJane Selgrade, chief of immunotoxicology at the EPA, learned by herself. With a PhD in medical microbiology, she moved into toxicology when she discovered that certain viruses enhance the toxicity of some compounds, rather than the compounds altering immunity to the viruses. "My career and the speciality of immunotoxicology grew up together," she recalls.

Jane Allen, too, taught herself, after training in microbiology and genetics. "I bought textbooks, read journals and attended meetings and continuing-education courses," says Allen, former director of toxicology for GlaxoSmithKline, who is now a consultant in Raleigh, North Carolina.

Toxicologists can maintain their skills with the help of continuing education programmes offered by such organizations as Eurotox, a European federation of individuals and societies, and IUTOX, the international union of toxicology, based in Reston, Virginia.

In the real world, people rarely encounter toxins in isolation. "We experience a suite of chemicals against a backdrop of different genetic backgrounds, drug exposures and foods — we need a combinatorial approach," says Birnbaum. So toxicology is moving away from analysing chemicals one at a time. A study in Salinas Valley, California, for example, probes the susceptibilities of Latino people to several pesticides in their environment. Beck is using a systems approach to analyse residual material on a medical implant.

Rory Conolly, a senior research biologist at the EPA, has been developing computer models of how multiple toxins affect the body since the early 1980s. "Because of the availability of deep data, people are realizing that the only way to deal with the avalanche is to be more sophisticated in how we analyse it — how to store, organize and apply advanced statistics to look for patterns in data," he says.

Toxicologists are such an enthusiastic bunch that many are stymied when asked to name a favourite investigation. Ramos's response is typical: "I have enjoyed every project I have ever worked on!" And with new tools to evaluate multi-layered data, that enthusiasm is certain to grow. "It is an exciting field with the potential for a lot of challenges over the next five to ten years," says Birnbaum.