Nriagu's contributions to science center around three main domains of environmental metal pollution: sources, behavior, fate and influence of toxic metals in the natural and contaminated environments; environmental justice within the framework of exposure assessment and health effects of toxic metals; and specific problems of environmental metal pollution in the developing countries. His research on emissions of trace metals from natural and
anthropogenic sources at the local, regional and global scales is the most widely recognized and cited. environmental chemistry of heavy metal phosphates which led to a technology for in-situ immobilization of lead in contaminated sites; first use of isotopic methods in fingerprinting the sources of the sulfur in the
Great Lakes Basin and the origin of lead in chocolates and cocoa products as well as the Great Lakes; in-depth studies of the behavior, fate and health risks associated with pollutant trace metals in lake ecosystems including the
North American Great Lakes. His study of the history of environmental metal pollution led to the book, ‘
Lead and Lead Poisoning in Antiquity and the evidence which implicates lead poisoning as a contributing factor in the decline of the Roman Empire. This hypothesis has been widely mentioned in the popular press and remains a topic of heated debate in the scientific literature.
Exposure assessment and environmental injustice Nriagu has made significant contributions in the development of advanced analytical protocols and in the study of the biomarkers of exposure and effects of various metals using body fluids and tissue sample; behavior of trace metals in the human oral environment; and forms of arsenic in groundwater and their influence on human
carcinogenesis. The understanding of the forms of heavy metals in foods (especially rice) and their health implications have also been advanced in his studies. Nriagu has contributed to knowledge on health disparities through his research on disproportionate exposure and poisoning of children with lead in many communities including the Arab-American and Black children in Detroit, the City of Saginaw, Michigan, the ger (
peri-urban) communities of Mongolia squatter camps of south-central Durban,
South Africa, and several urban areas of Nigeria. He has also conducted extensive studies of asthma prevalence and severity and their association with social, cultural and economic risk factors in the same communities as well as in Taipei in Taiwan. These studies were among the first to show significant positive association between childhood lead poisoning and asthma.
Growing threat of metal poisoning in developing countries Nriagu was among the first researchers to draw attention to emerging health risks associated with toxic metal pollution in Africa and publish on the
legacy pollution in South America from massive quantities of mercury used in production of silver and gold during colonial times. In addition to childhood asthma and lead poisoning, his research has addressed other specific threats of metal pollution in the developing countries including Brazil (mercury in fish from artisanal gold mining), Ghana (mercury pollution and poisoning in gold mining communities), Lake Victoria (
bioaccumulation of mercury in fish), South Africa (decline in children's blood lead in response to the phase-out of leaded gasoline), Nigeria (water quality, prenatal mercury exposure, and health effects of
oil pollution in the Niger Delta), Lebanon (environmental exposures to heavy metals and male infertility), India (exposure risks of arsenic in groundwater and local foods), Mongolia (multiple metal contamination of ground water), and Jamaica (natural contamination of local food chain with high levels of toxic metals in the soil). == Awards and honors ==