Lead (Pb) has been used by humans since prehistoric times to make tools due to its malleability and durability. The Roman Empire, the Industrial Revolution, and the introduction of Pb in gasoline during the 1920s contributed to increased environmental concentrations. Pb toxicity led to its removal from gasoline after several decades. However, Pb continues to be emitted from various anthropogenic sources, including but not limited to batteries, mining, foundries, smelting, e-waste recycling, and painting. Pb remains an environmental concern, as no established safe concentration for human health has been identified. Children are more susceptible to the absorption and poisoning of Pb. Occupational exposure to Pb poses a significant risk to workers and individuals living near lead industries. The primary routes of exposure are inhalation and ingestion, and bioaccumulation and biomagnification through the food chain are major sources of human exposure. This review aims to provide an overview of Pb and its systemic toxicity of Pb, including its effects on the lungs, blood, liver, kidneys, and nervous, cardiovascular, and reproductive systems. Since Pb is classified as a probable carcinogen for humans, the article also addresses genotoxicity and cancer risk. Furthermore, it reviews the most researched mechanisms of toxicity, including calcium mimicry, oxidative stress, and inflammation, along with other less-studied mechanisms. Nevertheless, the authors emphasize the importance of exploring less examined cells, tissues, and mechanisms to deepen the understanding of Pb toxicity at various concentrations, particularly in cases of chronic low-level Pb exposure, to develop better prevention and treatment strategies for lead poisoning.

Particulate atmospheric pollution poses a global threat to human health. Metals enter the body through inhalation attached to these particles. Certain vulnerable groups are more susceptible to toxicity because of age, physiological changes, and chronic and metabolic diseases and also workers because of high and cumulative exposure to metals. A narrative review was conducted to examine the effects of key metals—arsenic, cadmium, chromium, copper, lead, mercury, manganese, nickel, vanadium, and zinc—on vulnerable populations, analyzing articles published over the past decade. Some of these metals are essential for humans; however, excessive levels are toxic. Other non-essential metals are highly toxic. Shared mechanisms of toxicity include competing with other minerals, oxidative stress and inflammation, and interacting with proteins and enzymes. Prenatal and childhood exposures are particularly concerning because they can interfere with neurodevelopment and have been associated with epigenetic changes that have long-term effects. Occupational exposure has been studied, but current exposure limits for specific metals appear dangerous, emphasizing the need to revise these standards. Older adults, pregnant women, and individuals with metabolic diseases are among the least studied groups in this review, underscoring the need for more research to understand these populations better and create effective public health policies.

In this century, cancer is one of the most important causes of death worldwide, and the need for the development of new treatment options is imperative. The use of metal-based compounds in cancer treatment has increased significantly due to certain properties of these elements, and vanadium has been one of the most studied transition metals in recent decades. Vanadium compounds are being explored as an option for cancer treatment because of their wide range of action mechanisms such as the induction of oxidative stress, DNA damage, cell cycle arrest, induction of apoptosis and regulation of the autophagy process, among the most important mechanisms. Their compounds have been demonstrated to be effective against the cancer types with the highest incidence and mortality rates worldwide, such as lung and breast cancer, with promising results. This review discusses a variety of new vanadium compounds, indicating their mechanisms of action and the neoplasms in which they have shown effectiveness.

Revista de la Facultad de Medicina de la UNAM

Environmental pollution can promote oxidative stress by exposing the body to various elements and substances that generate free radicals, such as lead and vanadium. These free radicals can negatively impact the respiratory, cardiovascular, immune, and neurological systems of vulnerable populations, including children, the elderly, and those with chronic diseases. To prevent or reduce oxidative stress, it is recommended to consume a balanced diet rich in natural antioxidants. These antioxidants can be found in various foods, especially in fruits and vegetables with intense colors, seeds, and spices. In recent decades, the effectiveness of consuming natural antioxidants such as resveratrol (found in wine), coffee, curcumin, garlic, vitamin C, vitamin E, and green tea has been demonstrated. These antioxidants have beneficial effects on the body, including the protection of cell membranes, regulation of gene expression associated with inflammation, prevention or reduction of endothelial damage, and the decrease or diminished severity of neurodegeneration, liver, and pulmonary disorders. Additionally, they stimulate the immune response. Keywords: Free radicals; ROS; RNS; antioxidants; oxidative stress

La industrialización descontrolada en las urbes ha generado un problema de contaminación ambiental en todo el mundo. La emisión industrial de gases y vapores con compuestos tóxicos, aunado a la quema de combustibles fósiles son las principales fuentes de contaminación. Gran parte de los elementos metálicos y sus compuestos contaminan el aire, el suelo y los cuerpos de agua; algunos de ellos, como el cobre, el hierro o el manganeso, sirven de cofactores para enzimas que realizan funciones vitales, pero cuando los organismos se exponen a concentraciones mayores a las recomendadas, son potencialmente tóxicos. De otros metales se ha comprobado que no tienen funciones metabólicas en las células; por el contrario, son tóxicos, como son los casos del plomo, del cromo y del cadmio. Los efectos tóxicos de los metales conducen al deterioro de la salud e incluso pueden generar diferentes tipos de cáncer. Existe evidencia reportada de que diversos órganos son blancos de la toxicidad de los metales; por ejemplo, hay publicaciones que describen alteraciones respiratorias, neurológicas, cardiovasculares, hepáticas, renales, digestivas, inmunológicas, reproductivas, etc. Una vez que los metales ingresan al organismo se distribuyen por el torrente sanguíneo y entran a las células por canales iónicos o transportadores de metales esenciales. El daño celular por metales incluye la generación de estrés oxidante, mimetizar a los metales esenciales, producir daño genotóxico, modificar el ciclo celular, inhibir o inducir la expresión de genes y modular vías de señalización. En este trabajo se incluyen los principales mecanismos tóxicos de acción del cromo, del níquel, del cobre, del plomo, del cobalto, del manganeso, del cadmio y del vanadio, que son algunos de los metales reportados como contaminantes atmosféricos en México. Palabras clave: Contaminación atmosférica; metales pesados; toxicidad por metales; contaminación en México.