1 5683 147 SHORTER TELOMERE LENGTH IN PERIPHERAL BLOOD LYMPHOCYTES OF WORKERS EXPOSED TO POLYCYCLIC AROMATIC HYDROCARBONS. SHORTER TELOMERE LENGTH (TL) IN PERIPHERAL BLOOD LYMPHOCYTES (PBLS) IS PREDICTIVE OF LUNG CANCER RISK. POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) ARE ESTABLISHED LUNG CARCINOGENS THAT CAUSE CHROMOSOME INSTABILITY. WHETHER PAH EXPOSURE AND ITS MOLECULAR EFFECTS ARE LINKED WITH SHORTER TL HAS NEVER BEEN EVALUATED. IN THE PRESENT STUDY, WE INVESTIGATED THE EFFECT OF CHRONIC EXPOSURE TO PAHS ON TL MEASURED IN PBLS OF POLISH MALE NON-CURRENT SMOKING COKEOVEN WORKERS AND MATCHED CONTROLS. PAH EXPOSURE AND MOLECULAR EFFECTS WERE CHARACTERIZED USING MEASURES OF INTERNAL DOSE (URINARY 1-PYRENOL), EFFECTIVE DOSE [ANTI-BENZO[A]PYRENE DIOLEPOXIDE (ANTI-BPDE)-DNA ADDUCT], GENETIC INSTABILITY (MICRONUCLEI, MN) AND DNA METHYLATION [P53 PROMOTER AND ALU AND LONG INTERSPERSED NUCLEAR ELEMENT-1 (LINE-1) REPETITIVE ELEMENTS, AS SURROGATE MEASURES OF GLOBAL METHYLATION] IN PBLS. TL WAS MEASURED BY REAL-TIME POLYMERASE CHAIN REACTION. COKEOVEN WORKERS WERE HEAVILY EXPOSED TO PAHS (79% EXCEEDED THE URINARY 1-PYRENOL BIOLOGICAL EXPOSURE INDEX) AND EXHIBITED LOWER TL (P = 0.038) THAN CONTROLS, AS WELL AS HIGHER LEVELS OF GENETIC AND CHROMOSOMAL ALTERATIONS [I.E. ANTI-BPDE-DNA ADDUCT AND MN (P < 0.0001)] AND EPIGENETIC CHANGES [I.E. P53 GENE-SPECIFIC PROMOTER AND GLOBAL METHYLATION (P 3 MUMOL 1-PYRENOL/MOL CREATININE) SHOWED HIGHER MTDNACN [GEOMETRIC MEANS (GM) OF 1.06 (UNADJUSTED) AND 1.07 (AGE-ADJUSTED)] COMPARED WITH CONTROLS [GM 0.89 (UNADJUSTED); 0.89 (AGE-ADJUSTED); (P = 0.029 AND 0.016)], AS WELL AS HIGHER LEVELS OF GENETIC AND CHROMOSOMAL [I.E., ANTI-BPDE-DNA ADDUCTS (P < 0.001), MICRONUCLEI (P < 0.001), AND TELOMERE LENGTH (P = 0.053)] AND EPIGENETIC [I.E., P53 GENE-SPECIFIC PROMOTER METHYLATION (P < 0.001)] ALTERATIONS IN THE NDNA. IN THE WHOLE STUDY POPULATION, UNADJUSTED AND AGE-ADJUSTED MTDNACN WAS POSITIVELY CORRELATED WITH 1-PYRENOL (P = 0.043 AND 0.032) AND ANTI-BPDE-DNA ADDUCTS (P = 0.046 AND 0.049). CONCLUSIONS: PAH EXPOSURE AND PAH-RELATED NDNA GENOTOXICITY ARE ASSOCIATED WITH INCREASED MTDNACN. IMPACT: THE PRESENT STUDY IS SUGGESTIVE OF POTENTIAL ROLES OF MTDNACN IN PAH-INDUCED CARCINOGENESIS. 2013 4 5187 32 PRENATAL AIRBORNE POLYCYCLIC AROMATIC HYDROCARBON EXPOSURE, ALTERED REGULATION OF PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR GAMMA (PPAR)GAMMA, AND LINKS WITH MAMMARY CANCER. ENVIRONMENTAL EXPOSURE TO POLYCYCLIC AROMATIC HYDROCARBONS (PAH) HAS BEEN SHOWN TO BE ASSOCIATED WITH CHRONIC DISEASE OUTCOMES THROUGH MULTIPLE MECHANISMS INCLUDING ALTERED REGULATION OF THE TRANSCRIPTION FACTOR PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR GAMMA (PPAR) GAMMA. BECAUSE PAH EXPOSURE AND PPARGAMMA EACH HAVE BEEN ASSOCIATED WITH MAMMARY CANCER, WE ASKED WHETHER PAH WOULD INDUCE ALTERED REGULATION OF PPARGAMMA IN MAMMARY TISSUE, AND WHETHER THIS ASSOCIATION MAY UNDERLIE THE ASSOCIATION BETWEEN PAH AND MAMMARY CANCER. PREGNANT MICE WERE EXPOSED TO AEROSOLIZED PAH AT PROPORTIONS THAT MIMIC EQUIVALENT HUMAN EXPOSURES IN NEW YORK CITY AIR. WE HYPOTHESIZED THAT PRENATAL PAH EXPOSURE WOULD ALTER PPARGAMMA DNA METHYLATION AND GENE EXPRESSION AND INDUCE THE EPITHELIAL TO MESENCHYMAL TRANSITION (EMT) IN MAMMARY TISSUE OF OFFSPRING (F1) AND GRANDOFFSPRING (F2) MICE. WE ALSO HYPOTHESIZED THAT ALTERED REGULATION OF PPARGAMMA IN MAMMARY TISSUE WOULD ASSOCIATE WITH BIOMARKERS OF EMT, AND EXAMINED ASSOCIATIONS WITH WHOLE BODY WEIGHT. WE FOUND THAT PRENATAL PAH EXPOSURE LOWERED PPARGAMMA MAMMARY TISSUE METHYLATION AMONG GRANDOFFSPRING MICE AT POSTNATAL DAY (PND) 28. HOWEVER, PAH EXPOSURE DID NOT ASSOCIATE WITH ALTERED PPARGAMMA GENE EXPRESSION OR CONSISTENTLY WITH BIOMARKERS OF EMT. FINALLY, LOWER PPARGAMMA METHYLATION, BUT NOT GENE EXPRESSION, WAS ASSOCIATED WITH HIGHER BODY WEIGHT AMONG OFFSPRING AND GRANDOFFSPRING MICE AT PND28 AND PND60. FINDINGS SUGGEST ADDITIONAL EVIDENCE OF MULTI-GENERATIONAL ADVERSE EPIGENETIC EFFECTS OF PRENATAL PAH EXPOSURE AMONG GRANDOFFSPRING MICE. 2023 5 567 33 BASIC PROPERTIES AND MOLECULAR MECHANISMS OF EXOGENOUS CHEMICAL CARCINOGENS. EXOGENOUS CHEMICAL CARCINOGENESIS IS AN EXTREMELY COMPLEX MULTIFACTORIAL PROCESS DURING WHICH GENE-ENVIRONMENT INTERACTIONS INVOLVING CHRONIC EXPOSURE TO EXOGENOUS CHEMICAL CARCINOGENS (ECCS) AND POLYMORPHISMS OF CANCER SUSCEPTIBILITY GENES ADD FURTHER COMPLEXITY. WE DESCRIBE THE PROPERTIES AND MOLECULAR MECHANISMS OF ECCS THAT CONTRIBUTE TO INDUCE AND GENERATE CANCER. A BASIC AND SPECIFIC PROPERTY OF MANY LIPOPHILIC ORGANIC ECCS INCLUDING POLYCYCLIC AROMATIC HYDROCARBONS AND POLYHALOGENATED AROMATIC HYDROCARBONS IS THEIR ABILITY TO BIOACCUMULATE IN THE ADIPOSE TISSUE FROM WHERE THEY MAY BE RELEASED IN THE BLOOD CIRCULATION AND TARGET PERIPHERAL TISSUES FOR CARCINOGENESIS. MANY ORGANIC ECCS ARE PROCARCINOGENS AND CONSEQUENTLY NEED TO BE ACTIVATED BY THE CYTOCHROME P450 (CYP) SYSTEM AND/OR OTHER ENZYMES BEFORE THEY CAN ADDUCT DNA AND PROTEINS. BECAUSE THEY CONTRIBUTE NOT ONLY TO THE COCARCINOGENIC AND PROMOTING EFFECTS OF MANY AROMATIC POLLUTANTS BUT ALSO TO THEIR MUTAGENIC EFFECTS, THE ARYL HYDROCARBON RECEPTOR-ACTIVATING AND THE INDUCIBLE CYP SYSTEMS ARE CENTRAL TO EXOGENOUS CHEMICAL CARCINOGENESIS. ANOTHER BASIC PROPERTY OF ECCS IS THEIR ABILITY TO INDUCE STABLE AND BULKY DNA ADDUCTS THAT CANNOT BE SIMPLY REPAIRED BY THE DIFFERENT REPAIR SYSTEMS. IN ADDITION, FOLLOWING ECC EXPOSURE, MUTAGENESIS MAY ALSO BE CAUSED INDIRECTLY BY FREE-RADICAL PRODUCTION AND BY EPIGENETIC ALTERATIONS. AS A RESULT OF COMPLEX MOLECULAR INTERPLAYS, DIRECT AND/OR INDIRECT MUTAGENESIS MAY ESPECIALLY ACCOUNT FOR THE CARCINOGENIC EFFECTS OF MANY EXOGENOUS METALS AND METALLOIDS. BECAUSE OF THESE MOLECULAR PROPERTIES AND ACTION MECHANISMS, WE CONCLUDE THAT ECCS COULD BE MAJOR CONTRIBUTORS TO HUMAN CANCER, WITH OBVIOUSLY GREAT PUBLIC HEALTH CONSEQUENCES. 2010 6 1916 40 ENVIRONMENTAL AND OCCUPATIONAL EXPOSURE TO CHEMICALS AND TELOMERE LENGTH IN HUMAN STUDIES. TELOMERES ARE COMPLEXES OF TANDEM REPEATS OF DNA (5'-TTAGGG-3') AND PROTEIN THAT CAP EUKARYOTIC CHROMOSOMES AND PLAY A CRITICAL ROLE IN CHROMOSOME STABILITY. TELOMERES SHORTEN WITH AGING AND THIS PROCESS CAN BE ACCELERATED BY INCREASED OXIDATIVE STRESS AND EPISODES OF INFLAMMATION. EVIDENCE IS RAPIDLY GROWING THAT TELOMERE LENGTH (TL) MAY BE AFFECTED BY ENVIRONMENTAL CHEMICALS THAT HAVE FREQUENTLY BEEN ASSOCIATED WITH CHRONIC DISEASES. IN THIS ARTICLE, WE REVIEW THE PUBLISHED DATA ON TL IN RELATION TO ENVIRONMENTAL AND OCCUPATIONAL EXPOSURE TO SEVERAL CHEMICALS BASED ON OUR OWN AND OTHERS' STUDIES. THE ENVIRONMENTAL AND OCCUPATIONAL EXPOSURES ASSOCIATED WITH SHORTER TL INCLUDE TRAFFIC-RELATED AIR POLLUTION (IE, PARTICULATE MATTER (PM), BLACK CARBON (BC), AND BENZENE AND TOLUENE), POLYCYCLIC AROMATIC HYDROCARBONS (PAHS), N-NITROSAMINES, PESTICIDES, LEAD, EXPOSURE IN CAR MECHANICAL WORKSHOPS, AND HAZARDOUS WASTE EXPOSURE. ARSENIC, PERSISTENT ORGANIC POLLUTANTS (POPS) AND SHORT-TERM EXPOSURE TO PM ARE ASSOCIATED WITH LONGER TL. WE DISCUSS THE POSSIBLE REASONS FOR THE DIFFERENCES IN RESULTS, INCLUDING TIME- AND DOSE-RELATED ISSUES, STUDY DESIGN, AND POSSIBLE MECHANISMS INVOLVED IN TELOMERE REGULATION. WE ALSO DISCUSS THE FUTURE DIRECTIONS AND CHALLENGES FOR TL-RELATED ENVIRONMENTAL AND OCCUPATIONAL HEALTH RESEARCH, SUCH AS INVESTIGATION OF TL IN SUBPOPULATIONS OF BLOOD LEUKOCYTES, AND THE STUDY OF GENETIC AND EPIGENETIC FACTORS THAT MAY REGULATE TELOMERE INTEGRITY USING LONGITUDINAL DESIGNS. 2013 7 3710 45 INFLUENCES OF POLYCYCLIC AROMATIC HYDROCARBON ON THE EPIGENOME TOXICITY AND ITS APPLICABILITY IN HUMAN HEALTH RISK ASSESSMENT. THE EXISTENCE OF POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) IN AMBIENT AIR IS AN ESCALATING CONCERN WORLDWIDE BECAUSE OF THEIR ABILITY TO CAUSE CANCER AND INDUCE PERMANENT CHANGES IN THE GENETIC MATERIAL. GROWING EVIDENCE IMPLIES THAT DURING EARLY LIFE-SENSITIVE STAGES, THE RISK OF PROGRESSION OF ACUTE AND CHRONIC DISEASES DEPENDS ON EPIGENETIC CHANGES INITIATED BY THE INFLUENCE OF ENVIRONMENTAL CUES. SEVERAL REPORTS DECIPHERED THE RELATIONSHIP BETWEEN EXPOSURE TO ENVIRONMENTAL CHEMICALS AND EPIGENETICS, AND HAVE KNOWN TOXICANTS THAT ALTER THE EPIGENETIC STATES. AMONGST PAHS, BENZO[A]PYRENE (B[A]P) IS ACCEPTED AS A GROUP 1 CANCER-CAUSING AGENT BY THE INTERNATIONAL AGENCY FOR THE RESEARCH ON CANCER (IARC). B[A]P IS A WELL-STUDIED PRO-CARCINOGEN THAT IS METABOLICALLY ACTIVATED BY THE ARYL HYDROCARBON RECEPTOR (AHR)/CYTOCHROME P450 PATHWAY. CYTOCHROME P450 PLAYS A PIVOTAL ROLE IN THE STIMULATION STEP, WHICH IS ESSENTIAL FOR DNA ADDUCT FORMATION. ACCRUING EVIDENCE SUGGESTS THAT EPIGENETIC ALTERATIONS ASSUME A FUNDAMENTAL PART IN PAH-PROMOTED CARCINOGENESIS. THIS INTERACTION BETWEEN PAHS AND EPIGENETIC FACTORS RESULTS IN AN ALTERED PROFILE OF THESE MARKS, GLOBALLY AND LOCUS-SPECIFIC. SOME OF THE EPIGENETIC CHANGES DUE TO EXPOSURE TO PAHS LEAD TO INCREASED DISEASE SUSCEPTIBILITY AND PROGRESSION. IT IS WELL UNDERSTOOD THAT EXPOSURE TO ENVIRONMENTAL CARCINOGENS, SUCH AS PAH TRIGGERS DISEASE PATHWAYS THROUGH CHANGES IN THE GENOME. SEVERAL EVIDENCE REPORTED DUE TO THE EPIGENOME-WIDE ASSOCIATION STUDIES, THAT EARLY LIFE ADVERSE ENVIRONMENTAL EVENTS MAY TRIGGER WIDESPREAD AND PERSISTENT VARIATIONS IN TRANSCRIPTIONAL PROFILING. MOREOVER, THESE VARIATIONS RESPOND TO DNA DAMAGE AND/OR A CONSEQUENCE OF EPIGENETIC MODIFICATIONS THAT NEED FURTHER INVESTIGATION. GROWING EVIDENCE HAS ASSOCIATED PAHS WITH EPIGENETIC VARIATIONS INVOLVING ALTERATIONS IN DNA METHYLATION, HISTONE MODIFICATION, AND MICRO RNA (MIRNA) REGULATION. EPIGENETIC ALTERATIONS TO PAH EXPOSURE WERE RELATED TO CHRONIC DISEASES, SUCH AS PULMONARY DISEASE, CARDIOVASCULAR DISEASE, ENDOCRINE DISRUPTOR, NERVOUS SYSTEM DISORDER, AND CANCER. THIS HORMETIC RESPONSE GIVES A NOVEL PERCEPTION CONCERNING THE TOXICITY OF PAHS AND THE BIOLOGICAL REACTION THAT MAY BE A DISTINCT RELIANCE ON EXPOSURE. THIS REVIEW SHEDS LIGHT ON UNDERSTANDING THE LATEST EVIDENCE ABOUT HOW PAHS CAN ALTER EPIGENETIC PATTERNS AND HUMAN HEALTH. IN CONCLUSION, AS SEVERAL EPIGENETIC CHANGE MECHANISMS REMAIN UNCLEAR YET, FURTHER ANALYSES DERIVED FROM PAHS EXPOSURE MUST BE PERFORMED TO FIND NEW TARGETS AND DISEASE BIOMARKERS. IN SPITE OF THE CURRENT LIMITATIONS, NUMEROUS EVIDENCE SUPPORTS THE PERCEPTION THAT EPIGENETICS GRIPS SUBSTANTIAL POTENTIAL FOR ADVANCING OUR KNOWLEDGE ABOUT THE MOLECULAR MECHANISMS OF ENVIRONMENTAL TOXICANTS, ALSO FOR PREDICTING HEALTH-ASSOCIATED RISKS DUE TO ENVIRONMENTAL CIRCUMSTANCES EXPOSURE AND INDIVIDUAL SUSCEPTIBILITY. 2022 8 1919 25 ENVIRONMENTAL ENDOCRINE DISRUPTORS: NEW DIABETOGENS? THE PREVALENCE OF TYPE-2 DIABETES HAS DRAMATICALLY INCREASED WORLDWIDE DURING THE LAST FEW DECADES. WHILE LIFESTYLE FACTORS (SEDENTARINESS, NOXIOUS FOOD), TOGETHER WITH GENETIC SUSCEPTIBILITY, ARE WELL-KNOWN ACTORS, THERE IS ACCUMULATING EVIDENCE SUGGESTING THAT ENDOCRINE DISRUPTING CHEMICALS (EDCS) MAY ALSO PLAY A PATHOPHYSIOLOGICAL ROLE IN THE OCCURRENCE OF METABOLIC DISEASES. BOTH EXPERIMENTAL AND EPIDEMIOLOGICAL EVIDENCE SUPPORT A ROLE FOR EARLY AND CHRONIC EXPOSURE TO LOW DOSES OF CHEMICAL POLLUTANTS WITH ENDOCRINE AND METABOLIC DISRUPTING EFFECTS. MOST ARE PRESENT IN THE FOOD CHAIN AND ACCUMULATE IN THE FAT MASS AFTER ABSORPTION. IN RODENTS, BISPHENOL A STIMULATES SYNTHESIS AND SECRETION OF PANCREATIC BETA CELLS AND DISTURBS INSULIN SIGNALING IN LIVER, MUSCLE AND ADIPOSE TISSUE THROUGH EPIGENETIC CHANGES LEADING TO INSULIN RESISTANCE AND BETA CELL IMPAIRMENT. IN HUMANS, EPIDEMIOLOGICAL REPORTS SHOW STATISTICAL LINK BETWEEN EXPOSURE TO PESTICIDES, POLYCHLORINATED BISPHENYLS, BISPHENOL A, PHTHALATES, DIOXINS OR AROMATIC POLYCYCLIC HYDROCARBIDES OR HEAVY METALS AND DT2 AFTER ACUTE ACCIDENTAL RELEASES OR EARLY IN LIFE AND/OR CHRONIC, LOW DOSES EXPOSURE. MORE PROSPECTIVE, LONGITUDINAL STUDIES ARE NEEDED TO DETERMINE THE IMPORTANCE OF SUCH ENVIRONMENTAL RISK FACTORS. 2017 9 298 30 AIR POLLUTION AND AIRWAY DISEASE. EPIDEMIOLOGICAL AND TOXICOLOGICAL RESEARCH CONTINUES TO SUPPORT A LINK BETWEEN URBAN AIR POLLUTION AND AN INCREASED INCIDENCE AND/OR SEVERITY OF AIRWAY DISEASE. DETRIMENTAL EFFECTS OF OZONE (O(3)), NITROGEN DIOXIDE (NO(2)) AND PARTICULATE MATTER (PM), AS WELL AS TRAFFIC-RELATED POLLUTION AS A WHOLE, ON RESPIRATORY SYMPTOMS AND FUNCTION ARE WELL DOCUMENTED. NOT ONLY DO WE HAVE STRONG EPIDEMIOLOGICAL EVIDENCE OF A RELATIONSHIP BETWEEN AIR POLLUTION AND EXACERBATION OF ASTHMA AND RESPIRATORY MORBIDITY AND MORTALITY IN PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD), BUT RECENT STUDIES, PARTICULARLY IN URBAN AREAS, HAVE SUGGESTED A ROLE FOR POLLUTANTS IN THE DEVELOPMENT OF BOTH ASTHMA AND COPD. SIMILARLY, WHILE PREVALENCE AND SEVERITY OF ATOPIC CONDITIONS APPEAR TO BE MORE COMMON IN URBAN COMPARED WITH RURAL COMMUNITIES, EVIDENCE IS EMERGING THAT TRAFFIC-RELATED POLLUTANTS MAY CONTRIBUTE TO THE DEVELOPMENT OF ALLERGY. FURTHERMORE, NUMEROUS EPIDEMIOLOGICAL AND EXPERIMENTAL STUDIES SUGGEST AN ASSOCIATION BETWEEN EXPOSURE TO NO(2) , O(3) , PM AND COMBUSTION PRODUCTS OF BIOMASS FUELS AND AN INCREASED SUSCEPTIBILITY TO AND MORBIDITY FROM RESPIRATORY INFECTION. GIVEN THE CONSIDERABLE CONTRIBUTION THAT TRAFFIC EMISSIONS MAKE TO URBAN AIR POLLUTION RESEARCHERS HAVE SOUGHT TO CHARACTERIZE THE RELATIVE TOXICITY OF TRAFFIC-RELATED PM POLLUTANTS. RECENT ADVANCES IN MECHANISMS IMPLICATED IN THE ASSOCIATION OF AIR POLLUTANTS AND AIRWAY DISEASE INCLUDE EPIGENETIC ALTERATION OF GENES BY COMBUSTION-RELATED POLLUTANTS AND HOW POLYMORPHISMS IN GENES INVOLVED IN ANTIOXIDANT PATHWAYS AND AIRWAY INFLAMMATION CAN MODIFY RESPONSES TO AIR POLLUTION EXPOSURES. OTHER INTERESTING EPIDEMIOLOGICAL OBSERVATIONS RELATED TO INCREASED HOST SUSCEPTIBILITY INCLUDE A POSSIBLE LINK BETWEEN CHRONIC PM EXPOSURE DURING CHILDHOOD AND VULNERABILITY TO COPD IN ADULTHOOD, AND THAT INFANTS SUBJECTED TO HIGHER PRENATAL LEVELS OF AIR POLLUTION MAY BE AT GREATER RISK OF DEVELOPING RESPIRATORY CONDITIONS. WHILE THE CHARACTERIZATION OF POLLUTANT COMPONENTS AND SOURCES PROMISE TO GUIDE POLLUTION CONTROL STRATEGIES, THE IDENTIFICATION OF SUSCEPTIBLE SUBPOPULATIONS WILL BE NECESSARY IF TARGETED THERAPY/PREVENTION OF POLLUTION-INDUCED RESPIRATORY DISEASES IS TO BE DEVELOPED. 2011 10 5960 42 TELOMERE LENGTH IN HEPATOCELLULAR CARCINOMA AND PAIRED ADJACENT NON-TUMOR TISSUES BY QUANTITATIVE PCR. TELOMERE SHORTENING LIMITS THE PROLIFERATIVE CAPACITY OF HUMAN CELLS, RESTRAINS THE REGENERATIVE CAPACITY OF ORGAN SYSTEMS DURING CHRONIC DISEASES AND AGING AND ALSO INDUCES CHROMOSOMAL INSTABILITY AS WELL AS INITIATION OF CANCER. PREVIOUS STUDIES DEMONSTRATED THAT TELOMERES ARE OFTEN SIGNIFICANTLY SHORTER IN TUMOR TISSUE, INCLUDING HEPATOCELLULAR CARCINOMA (HCC), COMPARED TO THE SURROUNDING TISSUE, BUT TELOMERE LENGTH IN HCC TISSUES WAS NOT CORRELATED WITH SEVERAL CLINICAL PARAMETERS, SUCH AS AGE, SEX, HBV OR HCV INFECTIONS AND TUMOR SIZE. IN THE PRESENT STUDY, THE TELOMERE LENGTH RATIO OF 36 PAIRED HCC, AND THEIR ADJACENT NON-TUMOR TISSUES WAS MEASURED BY QUANTITATIVE PCR (Q-PCR). THE MEAN TELOMERE LENGTHS (SD) FOR HCC AND ADJACENT NON-TUMOR TISSUES WERE 0.26 (0.10) AND 0.47 (0.20) RESPECTIVELY (T = 6.22, P < 0.0001). THERE WAS A LARGE DIFFERENCE IN THE DISTRIBUTION OF SUBJECTS BASED ON TELOMERE LENGTH IN TUMOR AND ADJACENT NON-TUMOR TISSUES. THE NUMBER OF TUMORS WITH TELOMERE LENGTH SHORTER THAN 0.50 WAS MUCH HIGHER THAN THAT OF ADJACENT NON-TUMOR TISSUES; MORE THAN 90% OF THE TISSUES WITH TELOMERE LENGTH > OR = 0.50 WERE ADJACENT NON-TUMOR TISSUES. THE CORRELATIONS BETWEEN TELOMERE LENGTH AND AFLATOXIN B1- AND POLYCYCLIC AROMATIC HYDROCARBON-DNA ADDUCTS LEVEL, P53 MUTATIONS AND P16 HYPERMETHYLATION STATUS WERE ALSO TESTED, BUT NO SIGNIFICANT ASSOCIATIONS WERE FOUND. THE RELATIONSHIP BETWEEN TELOMERE LENGTH SHORTENING, CHEMICAL CARCINOGEN EXPOSURE, AND GENETIC AND EPIGENETIC CHANGES IN HEPATOCARCINOGENESIS NEEDS FURTHER INVESTIGATION. 2007 11 363 26 AMBIENT AIR POLLUTION: HEALTH HAZARDS TO CHILDREN. AMBIENT AIR POLLUTION IS PRODUCED BY SOURCES INCLUDING VEHICULAR TRAFFIC, COAL-FIRED POWER PLANTS, HYDRAULIC FRACTURING, AGRICULTURAL PRODUCTION, AND FOREST FIRES. IT CONSISTS OF PRIMARY POLLUTANTS GENERATED BY COMBUSTION AND SECONDARY POLLUTANTS FORMED IN THE ATMOSPHERE FROM PRECURSOR GASES. AIR POLLUTION CAUSES AND EXACERBATES CLIMATE CHANGE, AND CLIMATE CHANGE WORSENS HEALTH EFFECTS OF AIR POLLUTION. INFANTS AND CHILDREN ARE UNIQUELY SENSITIVE TO AIR POLLUTION, BECAUSE THEIR ORGANS ARE DEVELOPING AND THEY HAVE HIGHER AIR PER BODY WEIGHT INTAKE. HEALTH EFFECTS LINKED TO AIR POLLUTION INCLUDE NOT ONLY EXACERBATIONS OF RESPIRATORY DISEASES BUT ALSO REDUCED LUNG FUNCTION DEVELOPMENT AND INCREASED ASTHMA INCIDENCE. ADDITIONAL OUTCOMES OF CONCERN INCLUDE PRETERM BIRTH, LOW BIRTH WEIGHT, NEURODEVELOPMENTAL DISORDERS, IQ LOSS, PEDIATRIC CANCERS, AND INCREASED RISKS FOR ADULT CHRONIC DISEASES. THESE EFFECTS ARE MEDIATED BY OXIDATIVE STRESS, CHRONIC INFLAMMATION, ENDOCRINE DISRUPTION, AND GENETIC AND EPIGENETIC MECHANISMS ACROSS THE LIFE SPAN. NATURAL EXPERIMENTS DEMONSTRATE THAT WITH INITIATIVES SUCH AS INCREASED USE OF PUBLIC TRANSPORTATION, BOTH AIR QUALITY AND COMMUNITY HEALTH IMPROVE. SIMILARLY, THE CLEAN AIR ACT HAS IMPROVED AIR QUALITY, ALTHOUGH EXPOSURE INEQUITIES PERSIST. OTHER EFFECTIVE STRATEGIES FOR REDUCING AIR POLLUTION INCLUDE ENDING RELIANCE ON COAL, OIL, AND GAS; REGULATING INDUSTRIAL EMISSIONS; REDUCING EXPOSURE WITH ATTENTION TO PROXIMITY OF RESIDENCES, SCHOOLS, AND CHILD CARE FACILITIES TO TRAFFIC; AND A GREATER AWARENESS OF THE AIR QUALITY INDEX. THIS POLICY REVIEWS BOTH SHORT- AND LONG-TERM HEALTH CONSEQUENCES OF AMBIENT AIR POLLUTION, ESPECIALLY IN RELATION TO DEVELOPMENTAL EXPOSURES. IT EXAMINES INDIVIDUAL, COMMUNITY, AND LEGISLATIVE STRATEGIES TO MITIGATE AIR POLLUTION. 2021 12 1223 36 CRITICAL REVIEW ON EMERGING HEALTH EFFECTS ASSOCIATED WITH THE INDOOR AIR QUALITY AND ITS SUSTAINABLE MANAGEMENT. INDOOR AIR QUALITY (IAQ) IS ONE OF THE FUNDAMENTAL ELEMENTS AFFECTING PEOPLE'S HEALTH AND WELL-BEING. CURRENTLY, THERE IS A LACK OF AWARENESS AMONG PEOPLE ABOUT THE QUANTIFICATION, IDENTIFICATION, AND POSSIBLE HEALTH EFFECTS OF IAQ. AIRBORNE POLLUTANTS SUCH AS VOLATILE ORGANIC COMPOUNDS (VOCS), PARTICULATE MATTER (PM), SULFUR DIOXIDE (SO2), CARBON MONOXIDE (CO), NITROUS OXIDE (NO), POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) MICROBIAL SPORES, POLLEN, ALLERGENS, ETC. PRIMARILY CONTRIBUTE TO IAQ DETERIORATION. THIS REVIEW DISCUSSES THE SOURCES OF MAJOR INDOOR AIR POLLUTANTS, MOLECULAR TOXICITY MECHANISMS, AND THEIR EFFECTS ON CARDIOVASCULAR, OCULAR, NEUROLOGICAL, WOMEN, AND FOETAL HEALTH. ADDITIONALLY, CONTEMPORARY STRATEGIES AND SUSTAINABLE METHODS FOR REGULATING AND REDUCING POLLUTANT CONCENTRATIONS ARE EMPHASIZED, AND CURRENT INITIATIVES TO ADDRESS AND ENHANCE IAQ ARE EXPLORED, ALONG WITH THEIR UNIQUE ADVANTAGES AND POTENTIALS. DUE TO THEIR LONGER EXPOSURE TIMES AND PARTICULAR PHYSICAL CHARACTERISTICS, WOMEN AND CHILDREN ARE MORE AT RISK FOR POOR INDOOR AIR QUALITY. BY TRIGGERING MANY TOXICITY MECHANISMS, INCLUDING OXIDATIVE STRESS, DNA METHYLATION, EPIGENETIC MODIFICATIONS, AND GENE ACTIVATION, INDOOR AIR POLLUTION CAN CAUSE A RANGE OF HEALTH ISSUES. LOW BIRTH WEIGHT, ACUTE LOWER RESPIRATORY TRACT INFECTIONS, SICK BUILDING SYNDROMES (SBS), AND EARLY DEATH ARE MORE PREVALENT IN EXPOSED RESIDENTS. ON THE OTHER HAND, THE MAIN CAUSES OF INCAPACITY AND EARLY MORTALITY ARE LUNG CANCER, CHRONIC OBSTRUCTIVE PULMONARY DISEASE, AND CARDIOVASCULAR DISORDERS. IT'S CRUCIAL TO ACKNOWLEDGE ANTICIPATED RESEARCH NEEDS AND IMPLEMENTED EFFICIENT INTERVENTIONS AND POLICIES TO LOWER HEALTH HAZARDS. 2023 13 299 33 AIR POLLUTION AND DNA METHYLATION: EFFECTS OF EXPOSURE IN HUMANS. AIR POLLUTION EXPOSURE IS ESTIMATED TO CONTRIBUTE TO APPROXIMATELY SEVEN MILLION EARLY DEATHS EVERY YEAR WORLDWIDE AND MORE THAN 3% OF DISABILITY-ADJUSTED LIFE YEARS LOST. AIR POLLUTION HAS NUMEROUS HARMFUL EFFECTS ON HEALTH AND CONTRIBUTES TO THE DEVELOPMENT AND MORBIDITY OF CARDIOVASCULAR DISEASE, METABOLIC DISORDERS, AND A NUMBER OF LUNG PATHOLOGIES, INCLUDING ASTHMA AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). EMERGING DATA INDICATE THAT AIR POLLUTION EXPOSURE MODULATES THE EPIGENETIC MARK, DNA METHYLATION (DNAM), AND THAT THESE CHANGES MIGHT IN TURN INFLUENCE INFLAMMATION, DISEASE DEVELOPMENT, AND EXACERBATION RISK. SEVERAL TRAFFIC-RELATED AIR POLLUTION (TRAP) COMPONENTS, INCLUDING PARTICULATE MATTER (PM), BLACK CARBON (BC), OZONE (O(3)), NITROGEN OXIDES (NO(X)), AND POLYAROMATIC HYDROCARBONS (PAHS), HAVE BEEN ASSOCIATED WITH CHANGES IN DNAM; TYPICALLY LOWERING DNAM AFTER EXPOSURE. EFFECTS OF AIR POLLUTION ON DNAM HAVE BEEN OBSERVED ACROSS THE HUMAN LIFESPAN, BUT IT IS NOT YET CLEAR WHETHER EARLY LIFE DEVELOPMENTAL SENSITIVITY OR THE ACCUMULATION OF EXPOSURES HAVE THE MOST SIGNIFICANT EFFECTS ON HEALTH. AIR POLLUTION EXPOSURE-ASSOCIATED DNAM PATTERNS ARE OFTEN CORRELATED WITH LONG-TERM NEGATIVE RESPIRATORY HEALTH OUTCOMES, INCLUDING THE DEVELOPMENT OF LUNG DISEASES, A FOCUS IN THIS REVIEW. RECENTLY, INTERVENTIONS SUCH AS EXERCISE AND B VITAMINS HAVE BEEN PROPOSED TO REDUCE THE IMPACT OF AIR POLLUTION ON DNAM AND HEALTH. ULTIMATELY, IMPROVED KNOWLEDGE OF HOW EXPOSURE-INDUCED CHANGE IN DNAM IMPACTS HEALTH, BOTH ACUTELY AND CHRONICALLY, MAY ENABLE PREVENTATIVE AND REMEDIAL STRATEGIES TO REDUCE MORBIDITY IN POLLUTED ENVIRONMENTS. 2019 14 588 35 BENZENE EXPOSURE IS ASSOCIATED WITH EPIGENETIC CHANGES (REVIEW). BENZENE IS A VOLATILE AROMATIC HYDROCARBON SOLVENT AND IS KNOWN AS ONE OF THE PREDOMINANT AIR POLLUTANTS IN THE ENVIRONMENT. CHRONIC EXPOSURE TO BENZENE IS KNOWN TO CAUSE APLASTIC ANEMIA AND INCREASED RISK OF ACUTE MYELOGENOUS LEUKEMIA IN HUMANS. ALTHOUGH THE MECHANISMS BY WHICH BENZENE CAUSES TOXICITY REMAIN TO BE FULLY ELUCIDATED, IT IS WIDELY ACCEPTED THAT ITS METABOLISM IS CRUCIAL TO ITS TOXICITY, WITH INVOLVEMENT OF ONE OR MORE REACTIVE METABOLITES. NOVEL APPROACHES AIMED AT EVALUATING DIFFERENT MECHANISMS BY WHICH BENZENE CAN IMPACT ON HUMAN HEALTH BY ALTERING GENE REGULATION HAVE BEEN DEVELOPED. AMONG THESE NOVEL APPROACHES, EPIGENETICS APPEARS TO BE PROMISING. THE PRESENT REVIEW ARTICLE SUMMARIZES THE MOST IMPORTANT FINDINGS, REPORTED FROM THE LITERATURE, ON EPIGENETIC MODIFICATIONS CORRELATED TO BENZENE EXPOSURE. A COMPUTERIZED SEARCH IN PUBMED WAS PERFORMED IN NOVEMBER 2014, USING SEARCH TERMS, INCLUDING 'BENZENE', 'EPIGENETIC', 'HISTONE MODIFICATIONS', 'DNA METHYLATION' AND 'MICRORNA'. EPIDEMIOLOGICAL AND EXPERIMENTAL STUDIES HAVE DEMONSTRATED THE POTENTIAL EPIGENETIC EFFECTS OF BENZENE EXPOSURE. SEVERAL OF THE EPIGENOMIC CHANGES OBSERVED IN RESPONSE TO ENVIRONMENTAL EXPOSURES MAY BE MECHANISTICALLY ASSOCIATED WITH SUSCEPTIBILITY TO DISEASES. HOWEVER, FURTHER ELUCIDATION OF THE MECHANISMS BY WHICH BENZENE ALTERS GENE EXPRESSION MAY IMPROVE PREDICTION OF THE TOXIC POTENTIAL OF NOVEL COMPOUNDS INTRODUCED INTO THE ENVIRONMENT, AND ALLOW FOR MORE TARGETED AND APPROPRIATE DISEASE PREVENTION STRATEGIES. 2016 15 906 28 CHRONIC EXPOSURE TO ENVIRONMENTAL LEVEL PHENANTHRENE INDUCES NON-OBESITY-DEPENDENT INSULIN RESISTANCE IN MALE MICE. EPIDEMIOLOGICAL EVIDENCE SHOWS THAT THE BODY BURDEN OF POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) IS RELATED TO THE DISRUPTION OF GLUCOSE HOMEOSTASIS. HOWEVER, THE CONTRIBUTION OF PAHS TO THE DEVELOPMENT OF DIABETES REMAINS POORLY DOCUMENTED. IN THE CURRENT WORK, MALE KUNMING MICE RECEIVED PHENANTHRENE (PHE) (5, 50, AND 500 NG/KG) BY GAVAGE ADMINISTRATION ONCE EVERY 2 DAYS FOR 28 WEEKS. THE SIGNIFICANT ELEVATION OF HOMEOSTASIS MODEL ASSESSMENT-INSULIN RESISTANCE (HOMA-IR) AND HOMA-BETA CELL, ACCOMPANIED BY HYPERINSULINEMIA, INDICATED THE OCCURRENCE OF INSULIN RESISTANCE. THE SUPPRESSION OF THE INSULIN RECEPTOR SIGNALING PATHWAY IN SKELETAL MUSCLE MIGHT BE RESPONSIBLE FOR GLUCOSE INTOLERANCE. UNDER THE NONOBESE STATE, THE SERUM LEVELS OF RESISTIN, TUMOR NECROSIS FACTOR-ALPHA, AND INTERLEUKIN-6 WERE ELEVATED, WHEREAS THE LEVELS OF ADIPONECTIN WERE REDUCED. THESE CHANGES IN ADIPOCYTOKINE LEVELS WERE CONSISTENT WITH THEIR TRANSCRIPTION IN WHITE ADIPOSE TISSUE. THE PROMOTER METHYLATION LEVELS OF RETN (ENCODING RESISTIN) AND ADIPOQ (ENCODING ADIPONECTIN) WERE INVERSELY CORRELATED WITH THEIR MRNA LEVELS, INDICATING THAT PHE EXPOSURE COULD CAUSE THE DISRUPTION OF ADIPOCYTOKINE SECRETION VIA EPIGENETIC MODIFICATION. THE RESULTS WOULD BE HELPFUL FOR UNDERSTANDING THE PATHOGENESIS IN THE DEVELOPMENT OF T2DM CAUSED BY NONOBESOGENIC POLLUTANTS. 2020 16 1140 27 CONCENTRATION OF FOLIC ACID (FA) IN SERUM OF JAPANESE PREGNANT WOMEN. OBJECTIVES EXPOSURE TO INORGANIC ARSENIC (IAS) IS A WORLD-WIDE HEALTH CONCERN. WE REPORTED THAT JAPANESE CHILDREN AND PREGNANT WOMEN ARE EXPOSED TO MODERATE LEVELS OF IAS THROUGH FOOD. REDUCING IAS CONTAMINATION FROM FOODS OF HIGH IAS IS AN IMPORTANT ISSUE UNIQUE IN JAPAN. INTEGRATED IAS IS METHYLATED TO LESS TOXIC ORGANIC FORMS, AND S-ADENOSYL-L-METHYONINE (SAM), A COMMON METHYL-DONOR OF DNA AND HISTONES, IS UTILIZED IN THIS PROCESS. CHRONIC CONSUMPTION OF SAM BY IAS METABOLISM DUE TO EXPOSURE TO IAS MIGHT ALTER THE EPIGENETIC MODIFICATION OF GENOME. THE SAM BIOSYNTHESIS PATHWAY IS DEPENDENT ON FOLATE CYCLE, AND IT IS POSSIBLE THAT INGESTION OF SUFFICIENT FOLIC ACID (FA) IS PROTECTIVE TO IAS INDUCED TOXICITY. METHODS IN THE COURSE OF OUR CROSS-SECTIONAL BODY BURDEN ANALYSES OF PB AND IAS IN JAPANESE CHILDREN AND PREGNANT WOMEN, TERMED "PBAS STUDY", FA CONCENTRATION IN SERUM OF 104 PREGNANT WOMEN WAS MEASURED. RESULTS MEAN (+/-SEM) OF SERUM FA CONCENTRATION WAS 15.8 +/- 1.3 (NG/ML). THERE ARE SIGNIFICANT NUMBER OF PEOPLE SHOWING VERY HIGH FA (>30 NG/ ML), AND LARGE FRACTION OF THEM WERE TAKING SUPPLEMENTS DAILY. CONCLUSIONS THESE RESULTS SUGGESTED THAT LEVEL OF FA INGESTION OF JAPANESE PREGNANT WOMEN IS HIGH FOR SUPPORTING NORMAL FETAL DEVELOPMENT. 2020 17 2961 35 GENETIC AND EPIGENETIC MECHANISMS IN METAL CARCINOGENESIS AND COCARCINOGENESIS: NICKEL, ARSENIC, AND CHROMIUM. CHRONIC EXPOSURE TO NICKEL(II), CHROMIUM(VI), OR INORGANIC ARSENIC (IAS) HAS LONG BEEN KNOWN TO INCREASE CANCER INCIDENCE AMONG AFFECTED INDIVIDUALS. RECENT EPIDEMIOLOGICAL STUDIES HAVE FOUND THAT CARCINOGENIC RISKS ASSOCIATED WITH CHROMATE AND IAS EXPOSURES WERE SUBSTANTIALLY HIGHER THAN PREVIOUSLY THOUGHT, WHICH LED TO MAJOR REVISIONS OF THE FEDERAL STANDARDS REGULATING AMBIENT AND DRINKING WATER LEVELS. GENOTOXIC EFFECTS OF CR(VI) AND IAS ARE STRONGLY INFLUENCED BY THEIR INTRACELLULAR METABOLISM, WHICH CREATES SEVERAL REACTIVE INTERMEDIATES AND BYPRODUCTS. TOXIC METALS ARE CAPABLE OF POTENT AND SURPRISINGLY SELECTIVE ACTIVATION OF STRESS-SIGNALING PATHWAYS, WHICH ARE KNOWN TO CONTRIBUTE TO THE DEVELOPMENT OF HUMAN CANCERS. DEPENDING ON THE METAL, ASCORBATE (VITAMIN C) HAS BEEN FOUND TO ACT EITHER AS A STRONG ENHANCER OR SUPPRESSOR OF TOXIC RESPONSES IN HUMAN CELLS. IN ADDITION TO GENETIC DAMAGE VIA BOTH OXIDATIVE AND NONOXIDATIVE (DNA ADDUCTS) MECHANISMS, METALS CAN ALSO CAUSE SIGNIFICANT CHANGES IN DNA METHYLATION AND HISTONE MODIFICATIONS, LEADING TO EPIGENETIC SILENCING OR REACTIVATION OF GENE EXPRESSION. IN VITRO GENOTOXICITY EXPERIMENTS AND RECENT ANIMAL CARCINOGENICITY STUDIES PROVIDED STRONG SUPPORT FOR THE IDEA THAT METALS CAN ACT AS COCARCINOGENS IN COMBINATION WITH NONMETAL CARCINOGENS. COCARCINOGENIC AND COMUTAGENIC EFFECTS OF METALS ARE LIKELY TO STEM FROM THEIR ABILITY TO INTERFERE WITH DNA REPAIR PROCESSES. OVERALL, METAL CARCINOGENESIS APPEARS TO REQUIRE THE FORMATION OF SPECIFIC METAL COMPLEXES, CHROMOSOMAL DAMAGE, AND ACTIVATION OF SIGNAL TRANSDUCTION PATHWAYS PROMOTING SURVIVAL AND EXPANSION OF GENETICALLY/EPIGENETICALLY ALTERED CELLS. 2008 18 6909 30 [TOXIC COMPONENTS OF PM(2.5) AND THEIR TOXICITY MECHANISMS-ON THE TOXICITY OF SULFATE AND CARBON COMPONENTS]. RECENTLY, THE MAIN AIR POLLUTANT HAS BEEN FINE PARTICULATE MATTER (PM(2.5)), WHICH IS TAKEN UP BY THE WHOLE BODY WITH SEVERE ADVERSE HEALTH EFFECTS. THE MAIN CHEMICAL COMPONENTS OF PM(2.5) ARE SALTS OF SULFATE (AND NITRATE) AND CARBONS. HOWEVER, IT REMAINS UNKNOWN WHICH COMPONENTS ARE TOXIC. HERE, THE AUTHOR REVIEWED THE LITERATURES TO DETERMINE WHICH COMPONENTS ARE TOXIC AND THE MAIN MECHANISMS UNDERLYING THEIR TOXICITY. MANY EPIDEMIOLOGICAL STUDIES HAVE SHOWN THAT SULFATE CONCENTRATION IS STRONGLY RELATED TO MORTALITY. HOWEVER, THERE IS NO EXPERIMENTAL EVIDENCE SHOWING THAT SULFATE AT ENVIRONMENTAL CONCENTRATIONS OF PM(2.5) CAUSES CARDIOVASCULAR DISEASE OR OTHER DISEASE. ON THE OTHER HAND, CARBON COMPONENTS SUCH AS ELEMENTARY CARBON (EC) PRODUCES HIGH CONCENTRATIONS OF REACTIVE OXYGEN SPECIES (ROS) VIA ITS PHAGOCYTOSIS BY MACROPHAGES, AND ORGANIC CARBON (OC) ALSO PRODUCES HIGH CONCENTRATIONS OF ROS DURING ITS METABOLIC PROCESSES, AND THE ROS CAUSE ACUTE AND CHRONIC INFLAMMATION. THEY CAUSE MANY DISEASES INCLUDING CARDIOVASCULAR DISEASE, ASTHMA AND CANCER. FURTHERMORE, THERE ARE MANY LINES OF EVIDENCE SHOWING THAT EPIGENETIC CHANGES SUCH AS DNA METHYLATION OR MICRORNA EXPRESSION INDUCED BY PARTICULATE MATTERS ALSO INDUCE THE DEVELOPMENT OF MANY DISEASES SUCH AS THOSE MENTIONED ABOVE. IT HAS BEEN REPORTED THAT CARBON COMPONENTS ARE INCORPORATED INTO THE BRAIN AND PRODUCE ROS, AND THAT THE ROS CAUSE DAMAGE TO BRAIN CELLS AND ALZHEIMER'S DISEASE AND COGNITIVE DISORDERS IN THE ELDERLY.FROM THESE LINES OF EVIDENCE, THE AUTHOR WOULD LIKE TO EMPHASIZE THAT THE MAIN TOXICITY OF PM(2.5) IS DUE TO CARBON COMPONENTS, AND IT IS IMPORTANT TO TAKE COUNTERMEASURES TO DECREASE THE CONCENTRATION OF CARBON COMPONENTS IN AMBIENT AIR. 2019 19 1924 29 ENVIRONMENTAL EPIGENETICS AND ITS IMPLICATION ON DISEASE RISK AND HEALTH OUTCOMES. THIS REVIEW FOCUSES ON HOW ENVIRONMENTAL FACTORS THROUGH EPIGENETICS MODIFY DISEASE RISK AND HEALTH OUTCOMES. MAJOR EPIGENETIC EVENTS, SUCH AS HISTONE MODIFICATIONS, DNA METHYLATION, AND MICRORNA EXPRESSION, ARE DESCRIBED. THE FUNCTION OF DOSE, DURATION, COMPOSITION, AND WINDOW OF EXPOSURE IN REMODELING THE INDIVIDUAL'S EPIGENETIC TERRAIN AND DISEASE SUSCEPTIBILITY ARE ADDRESSED. THE IDEAS OF LIFELONG EDITING OF EARLY-LIFE EPIGENETIC MEMORIES, TRANSGENERATIONAL EFFECTS THROUGH GERMLINE TRANSMISSION, AND THE POTENTIAL ROLE OF HYDROXYLMETHYLATION OF CYTOSINE IN DEVELOPMENTAL REPROGRAMMING ARE DISCUSSED. FINALLY, THE EPIGENETIC EFFECTS OF SEVERAL MAJOR CLASSES OF ENVIRONMENTAL FACTORS ARE REVIEWED IN THE CONTEXT OF PATHOGENESIS OF DISEASE. THESE INCLUDE ENDOCRINE DISRUPTORS, TOBACCO SMOKE, POLYCYCLIC AROMATIC HYDROCARBONS, INFECTIOUS PATHOGENS, PARTICULATE MATTER, DIESEL EXHAUST PARTICLES, DUST MITES, FUNGI, HEAVY METALS, AND OTHER INDOOR AND OUTDOOR POLLUTANTS. WE CONCLUDE THAT THE SUMMATION OF EPIGENETIC MODIFICATIONS INDUCED BY MULTIPLE ENVIRONMENTAL EXPOSURES, ACCUMULATED OVER TIME, REPRESENTED AS BROAD OR NARROW, ACUTE OR CHRONIC, DEVELOPMENTAL OR LIFELONG, MAY PROVIDE A MORE PRECISE ASSESSMENT OF RISK AND CONSEQUENCES. FUTURE INVESTIGATIONS MAY FOCUS ON THEIR USE AS READOUTS OR BIOMARKERS OF THE TOTALITY OF PAST EXPOSURE FOR THE PREDICTION OF FUTURE DISEASE RISK AND THE PRESCRIPTION OF EFFECTIVE COUNTERMEASURES. 2012 20 2940 43 GENETIC AND EPIGENETIC ALTERATIONS IN NORMAL AND SENSITIVE COPD-DISEASED HUMAN BRONCHIAL EPITHELIAL CELLS REPEATEDLY EXPOSED TO AIR POLLUTION-DERIVED PM(2.5). EVEN THOUGH CLINICAL, EPIDEMIOLOGICAL AND TOXICOLOGICAL STUDIES HAVE PROGRESSIVELY PROVIDED A BETTER KNOWLEDGE OF THE UNDERLYING MECHANISMS BY WHICH AIR POLLUTION-DERIVED PARTICULATE MATTER (PM) EXERTS ITS HARMFUL HEALTH EFFECTS, FURTHER IN VITRO STUDIES ON RELEVANT CELL SYSTEMS ARE STILL NEEDED. HENCE, AIMING OF GETTING CLOSER TO THE HUMAN IN VIVO CONDITIONS, PRIMARY HUMAN BRONCHIAL EPITHELIAL CELLS DERIVED FROM NORMAL SUBJECTS (NHBE) OR SENSITIVE CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD)-DISEASED PATIENTS (DHBE) WERE DIFFERENTIATED AT THE AIR-LIQUID INTERFACE. THEREAFTER, THEY WERE REPEATEDLY EXPOSED TO AIR POLLUTION-DERIVED PM(2.5) TO STUDY THE OCCURRENCE OF SOME RELEVANT GENETIC AND/OR EPIGENETIC ENDPOINTS. CONCENTRATION-, EXPOSURE- AND SEASON-DEPENDENT INCREASES OF OH-B[A]P METABOLITES IN NHBE, AND TO A LESSER EXTENT, COPD-DHBE CELLS WERE REPORTED; HOWEVER, THERE WERE MORE TETRA-OH-B[A]P AND 8-OHDG DNA ADDUCTS IN COPD-DHBE CELLS. NO INCREASE IN PRIMARY DNA STRAND BREAK NOR CHROMOSOMAL ABERRATION WAS OBSERVED IN REPEATEDLY EXPOSED CELLS. TELOMERE LENGTH AND TELOMERASE ACTIVITY WERE MODIFIED IN A CONCENTRATION- AND EXPOSURE-DEPENDENT MANNER IN NHBE AND PARTICULARLY COPD-DHBE CELLS. THERE WERE A GLOBAL DNA HYPOMETHYLATION, A P16 GENE PROMOTER HYPERMETHYLATION, AND A DECREASING DNA METHYLTRANSFERASE ACTIVITY IN NHBE AND NOTABLY COPD-DHBE CELLS REPEATEDLY EXPOSED. CHANGES IN SITE-SPECIFIC METHYLATION, ACETYLATION, AND PHOSPHORYLATION OF HISTONE H3 (I.E., H3K4ME3, H3K9AC, H3K27AC, AND H3S10PH) AND RELATED ENZYME ACTIVITIES OCCURRED IN A CONCENTRATION- AND EXPOSURE-DEPENDENT MANNER IN ALL THE REPEATEDLY EXPOSED CELLS. COLLECTIVELY, THESE RESULTS HIGHLIGHTED THE KEY ROLE PLAYED BY GENETIC AND EVEN EPIGENETIC EVENTS IN NHBE AND PARTICULARLY SENSITIVE COPD-DHBE CELLS REPEATEDLY EXPOSED TO AIR POLLUTION-DERIVED PM(2.5) AND THEIR DIFFERENT RESPONSIVENESS. WHILE THESE SPECIFIC EPIGENETIC CHANGES HAVE BEEN ALREADY DESCRIBED IN COPD AND EVEN LUNG CANCER PHENOTYPES, OUR FINDINGS SUPPORTED THAT, TOGETHER WITH GENETIC EVENTS, THESE EPIGENETIC EVENTS COULD DRAMATICALLY CONTRIBUTE TO THE SHIFT FROM HEALTHY TO DISEASED PHENOTYPES FOLLOWING REPEATED EXPOSURE TO RELATIVELY LOW DOSES OF AIR POLLUTION-DERIVED PM(2.5). 2017