According to the Current Population Survey (2009-2010), close to one of every three workers in the United States (approximately 39 million workers) was low-income (Table I), defined as weekly earnings below 150% of the federal minimum wage for a 40-hour workweek (currently $435). Low income workers were disproportionately women, African-American, Hispanic, foreign-born, lacking a high school diploma, and under 24 years of age. The most common occupations of low income workers included cashiers, food service workers, personal and home care aides, housekeepers, hand packagers, farm workers and child care workers (Table II). The low-income workforce is likely to remain large, since over half of the approximately 51 million job openings projected between 2008 and 2018 require no postsecondary education [U.S. Bureau of Labor Statistics, 2009].

Many studies have demonstrated associations between income level and overall life expectancy [e.g., Clarke et al., 2010; Lin et al., 2003; Singh and Siahpush, 2006] and rates of chronic disease including diabetes, hypertension and obstructive lung diseases [e.g. Braveman et al., 2011; Diez Roux et al., 2002; Kanervisto et al., 2011; Kanjilal et al.; 2006]. These disparities in health are also considered to be health inequities, because they often arise from social disadvantage which has created modifiable and ethically unfair exposures at work, at home, and in the community [Braveman, 2010; Centers for Disease Control and Prevention, 2011; Krieger et al., 2008].

Several of the most common low-income occupations are also among those with the highest numbers of work-related injuries and illnesses [Bureau of Labor Statistics, 2010]. Thus unsafe and unhealthy working conditions represent one possible mechanism by which health disparities may arise [Boyer et al., 2009; Chandola et al., 2005; d'Errico et al., 2007].

Other health-promoting factors, such as neighborhood walkability, availability of healthy food, and physical safety in the community, are often inadequate in low-income communities [Mujahid et al., 2008; Hutch et al., 2011; Woolf et al., 2011]. Low-income workers, especially those from racial and ethnic minority communities, are also more likely to live in communities with higher levels of air, water and soil contamination [Morello-Frosch and Jesdale, 2006]. People of color make up the majority (56%) of those living within two miles of the nation's commercial hazardous waste facilities; an even larger majority (69%) lives in neighborhoods with multiple hazardous waste facilities [Bullard et al., 2007]. Low-income and minority populations also have more difficulty accessing safe and healthy housing [USDHHS, 2009]. Experiences of racism and other forms of discrimination may have additional health effects [Krieger et al., 1996]. Thus, many lower income individuals face multiple levels of unhealthy exposures at work, in the community and at home.

Some characteristics of low-income occupations limit the information available about health the impact of working conditions in these groups. Many low-wage workers are employed by small establishments, and small companies are less likely to report occupational injuries to the Bureau of Labor Statistics' Survey of Occupational Injuries and Illnesses (SOII) [Souza et al., 2010; Dong et al., 2011]. Low-wage workers may be more susceptible to pressure from employers not to report occupational injuries or file workers' compensation claims [Azaroff et al., 2002; Lowry et al., 2010]. Those low-wage workers hired as independent contractors are frequently not covered by their employers' workers compensation programs, and so illness and injuries in these workers would not be detected in reviews of compensation claims [NAIC, 2008].

The many problems faced by low-income workers and the complex interplay of overlapping occupational and non-occupational issues pose significant challenges. These are exacerbated by the lack of effective public health programs to address the multiple and interacting sources of risk. The separation of different health hazards into disciplinary “silos” occurs in academia as well as by practitioners in workplaces, community and clinical settings. Until recently, with a few exceptions [DeJoy and Southern 1993], few public health professionals even envisioned more holistic programs to address low-income workers' health [Campe, et al. 2011].

Traditionally, worksite health programs have either addressed lifestyle habits such as cigarette smoking and weight control or workplace environmental conditions such as chemical exposures or heavy lifting; these are rarely combined as part of an integrated program [Cherniack et al., 2011; Sorensen et al., 2011]. A more fundamental issue, however, is the scope of most worksite health programs rarely attend to or even acknowledge the larger social, economic and political context that influences health behaviors, work and community environmental conditions, and access to jobs.

Worksite health promotion (WHP) programs typically focus predominately on addressing personal “lifestyle” through education and screening activities aimed at increasing individual workers' awareness of personal risk factors and suggesting strategies to modify health behaviors. Some have also involved institutional changes in the workplace to promote healthy behaviors, such as providing exercise facilities, labeling vending machines with nutritional information, and preferentially pricing healthy choices in worksite cafeterias [Pratt, et al. 2007]. Few WHP programs reach the one-half or more of U.S. workers in small companies or scattered in small numbers across multiple sites [Linnan, et al. 2008].

The scope of many traditional WHP programs ignores the contribution of work-related exposures to illness. One example would be a program that focuses only on smoking cessation for workers exposed to asthmagens or other substances that cause lung disease. When employers ignore workplace environmental conditions which are of concern to employees, then health messages and other WHP programming may be less effective [Sorensen et al., 2002; Cherniack et al., 2011]. The new National Healthy Worksite Program of the CDC explicitly calls for identification of occupational health and safety concerns as part of the needs assessment process to implement a workplace health promotion program [CDC 2012].

Failure to consider work organization factors can also limit the success of WHPs. Shift scheduling, involuntary overtime, lack of affordable childcare, lack of adequate transportation, employee medical insurance coverage and sick leave, and low wages may all directly affect workers' access, free time, or ability to exercise or prepare healthy meals. Factors in the work environment including night work, work pace, occurrence of assaults, low decision latitude and other psychosocial stressors can all increase the prevalence of risk factors such as cigarette smoking, alcohol use, unhealthy eating patterns, lack of leisure-time exercise, and obesity [Albertsen et al., 2006; Brisson et al., 2000; Chandola et al., 2005; Kouvonen et al., 2005; Kouvonen et al., 2005; KivimÄki et al., 2001; Ostry et al.; 2006; Parkes, 2002; Vaananen et al., 2009; Wemme and Rosvall, 2005]. Low-income workers have reported their eating and exercise behaviors to be adversely affected by time pressure, physical fatigue, and low control over workload and scheduling, as well as by limited food options in the workplace [Champagne et al., 2012].

An underlying goal of health promotion is to motivate healthy decision-making by individuals. Therefore, the work environment itself should reinforce employee competence in decision-making [Koelen and Lindstrom 2005; Punnett et al., 2009]. If the work environment is experienced as negating the individual's autonomy and decision-making capacities, then the entire strategy underlying WHP is contradicted. Many low-income workers have no job decision-making authority or opportunities to use and develop their skills at work. Workers in these types of jobs, with low “decision latitude,” may develop a lower sense of self-efficacy, becoming more passive in relation to their life circumstances [Karasek and Theorell 1990]. Conversely, greater decision latitude, realized through participating in a work team towards a common goal or having a voice through one's union, can increase satisfaction and self-efficacy [Delp et al., 2010; Park et al., 2004; Watts et al., 2001].

Worker input is also important in designing a program that is relevant and acceptable to workers [Punnett et al., 2009; Henning et al., 2009]. A genuinely participatory structure increases the likelihood that the WHP program will be relevant to workers, enhancing the environmental features that are supports and addressing those that are obstacles to healthy behaviors. One example of a participatory program engaging low-income workers to integrate health protection and health promotion (Table IV) was developed through one of the NIOSH-funded Centers of Excellence to Promote a Healthier Workforce (http://www.cdc.gov/niosh/TWH/centers.html).

Achieving health equity for all groups is an overarching goal in Healthy People, a set of recommendations designed to guide public health efforts nationwide [USDHHS 2010]. State and local public health programs directly target special populations such as low-income women, adolescents, immigrants, minorities and people with disabilities. Public health agencies are in a position to intervene at multiple levels of the SEF—by shaping policy and promoting systems change at the workplace and in the community, as well as by offering individually focused education and preventive services and assuring access to care [Davis and Souza, 2009].

The state and local public health infrastructure can provide many points of access to reach underserved worker groups with information about health and safety risks, and with strategies to control hazards, provide occupational health services and provide information about legal rights. Public health agencies in a number of states have, for example, disseminated information about health risks in cosmetology through local public health sanitarians responsible for inspecting beauty salons. Health departments in Connecticut (personal communication: Thomas St. Louis, Connecticut Department of Public Health) and in the San Francisco Bay Area [Gaydos et al., 2011] have conducted outreach about worker safety hazards in restaurants through food safety inspectors. In Massachusetts, the public health department disseminates information about young worker health and safety through the school health network (e.g. www.mass.gov/dph/teensatwork) and is increasingly using social media to publicize health and safety risks, such as public health podcasts in Portuguese and Spanish on safety risks in residential construction. Important targets for these outreach efforts are specific cultural outlets including media [Calles-Escandon et al. 2009] which in turn disseminate the information to their constituents. US public health agencies could replicate a Canadian program that has disseminated basic information about health and safety rights and resources to newcomers through refugee resettlement programs [Institute for Work and Health, 2011]. These mainstream public health avenues of communication can also serve as important two-way streets through which health departments not only provide occupational health and safety information and services, but also collect information from community members about their work and other life experiences that influence health. The occupational public health program in New Hampshire, for example, has collaborated with their Office of Minority Health and Refugee Affairs to identify community leaders to facilitate focus groups to collect information about health and safety needs of immigrants and refugees (personal communication: Karla Armenti, New Hampshire Division of Public Health Services).

State health departments can also coordinate public health collaborations that arise when health concerns of workers and the public-at-large clearly intersect. Many health hazards such as indoor air quality in schools, latex exposure in health care settings, and lead exposure in home renovation, threaten the health both of workers and of the general public. These shared hazards demand policy and practice solutions that protect all those at risk. Interventions driven largely by concern for the public can result in secondary gains for workers and vice versa. In California, the health department's Cleaning for Asthma-Safe Schools project promotes safer cleaning in schools to protect custodians, school staff, and students(Website: http://www.cdph.ca.gov/programs/ohsep/Pages/class.aspx, accessed 12/19/2012). In Oregon, concern about resident and worker exposure to commercial pesticides in homes led to changes in training for emergency responders; collaboration among multiple state health agencies conducting pesticide surveillance has led to changes in national pesticide labeling to protect consumers and workers alike (CSTE, 2012). These collaborations between occupational health and other public health disciplines bring together their distinct but complementary community networks— leading not just to shared knowledge but also to an expanded advocacy base to prevent workplace and community exposures.

Truly integrative programs address the complex interplay among factors at work, at home and in the broader environment. Important opportunities occur when the public health focus is on outcomes such as violence, cardiovascular disease and asthma for which occupational risks are among the contributing factors. Integrating occupational health concerns into strategic public health planning can set the stage for future actions and resource allocation . For example, in New Jersey, addressing occupational asthma is included on the state's asthma agenda and these efforts have promoted increased recognition of the need for asthma prevention as well as environmental control . In Michigan, a multidisciplinary team, including occupational health professionals, conducts case reviews of sudden asthma death and often uncovers workplace causes that can be addressed (http://www.oem.msu.edu/Asthma.aspx, accessed 12-2-12; Chester et al., 2005). In Massachusetts, workplace violence is now included on the state's agenda to reduce youth violence; consequently health and safety training has been integrated into a number of youth violence prevention programs. Likewise, workplace stress is on the statewide strategic plan to address cardiovascular disease, which has resulted in initiatives to develop integrative approaches to worksite wellness that address both personal and occupational risk factors [Davis and Souza 2009]. In Connecticut, the occupational public health program has partnered with the state health department's cardiovascular health initiative to develop the HEARTSafe Workplace certification program, aimed at reducing workplace hazards and other risk factors and training in cardiac event response (CSTE, 2012). In California, health department occupational and environmental health programs have joined forces to train promotores (Latino/a community health workers) throughout the state on environmental and occupational health issues and are working to develop a 40 hour environmental health curriculum, which will include training on occupational health[CDPH, 2012].

Public health agencies also influence population health through policy initiatives, developing public health regulations (such as mandatory reporting of lead poisonings) and bringing stakeholders (including other state agencies, such as state OSHA or environmental quality programs) together to address critical public health problems. State health agencies, which have the legal authority to require disease reporting and to collect health data, can also play an essential role in documenting health disparities [Souza, et al. 2010]. They have access to many health data sources and can document occupational health needs of vulnerable groups that are not well captured in the SOII and workers' compensation data sets. For example, clinical laboratory data on elevated blood lead levels has been used to document the high risk of lead poisoning among Hispanics adults [Tak et al., 2008]. A joint NIOSH-state initiative is underway to incorporate occupational information in the Behavioral Risk Factor Surveillance System, which will allow opportunities to examine a range of health outcomes in relation to work and other socio-economic variables.

Many public health programs currently focus on individual-level health education programs, but there is renewed recognition of the need for systematic institutional or organizational changes to improve health [Frieden 2010] and new opportunities for integrative approaches – both programs and policies - to improve the health of low-income workers. With an increasing number of state health and labor agencies developing occupational public health programs in recent years – 23 states were funded by NIOSH in 2011 to implement fundamental programs – there is a growing platform on which to build collaborative efforts.

The working poor are disproportionately un- or under-insured for medical services. In 2010, 43% of lower income working age adults (18–64 year olds with an income between 100-200% of the poverty level) were uninsured [Cohen, et al. 2011]. Lack of health care access causes delays in early diagnosis and treatment and contributes to health inequities [Smedley et al., 2003]. Many workers face added barriers to access health services for work-related injuries and illnesses [Leigh and Robbins 2004]. Obstacles to using workers' compensation have been widely documented [Dembe, 2001; Boden 2012]. A 2007 survey in 10 states found the median proportion of those injured at work whose medical treatment was paid for by workers compensation was only 61% [Centers for Disease Control and Prevention, 2010]. Failure to use workers' compensation may not only interfere with access to medical care but also precludes workers' ability to access wage benefits necessary to support themselves and their families during recovery or if disabled.

Community and Migrant Health Centers (C/MHCs) are direct-care providers serving the poor (including the working poor), the uninsured, the homeless, immigrants and refugees, and migrant and seasonal farmworkers, among others. They are supported in part by the Health Resources and Services Administration (HRSA), Department of Health and Human Services, and operate in more than 8,000 locations, serving 23 million patients throughout the US (http://bphc.hrsa.gov/about/index.html). They are an important healthcare safety net for the medically indigent, including workers who are likely to seek care for health problems that are caused or compounded by their work exposures [Earle-Richardson et al., 2008],

C/MHCs are often the first point of access for low-income workers seeking care for work-related or non work-related health concerns. Even for workers who have access to occupational health services within their workplaces, job insecurity and fears of retaliation (firing or being labeled a “careless” employee) means that many low-income workers are seen in C/MHCs for work-related problems [Azaroff et al., 2004]. Often uninsured workers are not aware that they are entitled to medical care for work-related health problems through workers compensation insurance. In five C/MHCs in Massachusetts, over 1400 working or recently unemployed patients completed a short, anonymous survey. Twenty-one percent reported experiencing a work-related injury, illness, or other health problem during the previous year, yet 39% of those experiencing a work-related health problems had never heard of workers' compensation and 63% had never heard of the Occupational Safety and Health Administration [Massachusetts Department of Public Health, 2007].

The health care providers at community health centers, like many other primary care providers (PCPs), frequently lack the knowledge or skills to address these occupational health needs. Among C/MHC clinicians surveyed by the Massachusetts Department of Public Health, only one-third reported having adequate training to help patients with injuries or illnesses caused by their jobs, and only 10% thought they had adequate educational or resource materials to offer patients who might be exposed to hazards on the job (personal communication: Letitia Davis). A review of chart notes for patients with chronic obstructive pulmonary disease in primary care practices found that, while 90% of the time the provider documented the individual's occupation, and most patients reported a history of occupational exposures to respirable hazards, a recommendation to avoid exposure was made in only 10% of the cases [Kuschner et al., 2009]. A similar chart review among patients with newly diagnosed asthma found that job title was documented in 75% of cases, but exposure data were collected less frequently and clinical action to address occupational asthma was taken in only 1 case [Shofer et al., 2006]. These findings are not surprising, given the limited attention paid to occupational and environmental health in medical and nursing school curricula [Gehle et al., 2011; Goldman et al.,1999; McCurdy et al., 2004; Schenk et al.,1996].

Greater collaboration between occupational health practitioners and PCPs improves patient care and facilitates opportunities for intervention at multiple levels of the SEF framework. Practitioners in C/MHCs bring valuable experience with linguistic and cultural competency, an understanding of the role of social factors in determining an individual's health and access to community support services [Kugel and Zuroweste, 2010; Adashi et al., 2010]. Occupational health practitioners can share their knowledge and skills in diagnosis and treatment of work-related health problems and provide an increased understanding of the reality of people's work lives. Several model programs have been developed to assist primary care providers in providing more comprehensive care by better integrating risk factors related to the work environment through specialty consultation programs and by providing easy access to information through toll free hotlines. For example, the New York State Occupational Clinic Network, funded through the state worker's compensation fund, provides consultation to health care providers treating patients with potentially work-related illnesses and injuries and also assists professionals and patients to deal with the workers' compensation system [Herbert et al., 2000].Table V illustrates how these kinds of consultation services have helped clinicians and patients in community health centers serving agricultural workers. Massachusetts has also piloted the collection of information about occupation in electronic health records at several CHCs, which may improve recognition and diagnosis of work-related health problems and management of care for patients more generally [Wegman et al. 2011].

While historically most community-based health programs were offered through community health centers or local health departments, more recently other community organization have initiated or are playing central roles in programs to promote health equity, including programs to reduce environmental and occupational exposures. These intervention programs, often referred to as community-based participatory programs, prioritize the active participation by community members in the development, implementation and evaluation of programs [Wallerstein and Duran, 2010]. These programs embrace the SEF framework by looking beyond individual risk factors and health behaviors to examine broader social and community influences on health [Minkler, 2010].

A community-based participatory approach is useful in reaching many low income workers, especially those workers whose employers are unwilling or unable to address occupational safety and health issues (such as small business owners) or for workers who may feel intimidated at the workplace [Minkler et al., 2010]. They are also effective in developing education and outreach programs that overcome the cultural, language, and literacy barriers that limit the effectiveness of some workplace training programs [Baron et al., 2009]. Finally, by building local knowledge and leadership these approaches help to create sustainable programs [Israel et al., 2010; Minkler et al., 2008]. Many of these characteristics are demonstrated in the community-based training initiative for contingent Latino workers described in Table VI.

Environmental Justice: Partnerships for Communication is an example of a federally funded community-based participatory research (CBPR) initiative addressing environmental and occupational health [Baron et al., 2009]. This program was first funded in 1994 by the National Institute of Environmental Health Sciences (NIEHS) to allow community members to actively participate in the environmental and occupational health research affecting their communities. By 2007, NIEHS, together with EPA and NIOSH, had funded a total of 53 projects in urban and rural communities throughout the US. The projects brought together three groups—community organizations, environmental/occupational health researchers, and health care professionals—to address the needs of communities facing disproportionate health and environmental burdens. They emphasized community engagement to encourage individual behavior change and to motivate collective actions to create sustainable programs and improve policies, thus implicitly adopting the SEF. The projects raised health awareness at the intrapersonal and interpersonal levels through community classes and workshops, educational presentations in community centers and religious institutions, and technical information meetings in response to specific community complaints. “Neighbor to neighbor” community outreach strategies, often by community health workers, developed portable illustrated flip charts, photos for digital storytelling and interactive exercises. They also used mass media outlets including radio, television and newspapers; and created educational fact sheets and pamphlets, posters, video/DVDs, audio cassettes, photo exhibits, and community theater performances [Adams et al., 2011; Azuma et al., 2010; Baron et al., 2009; Brody et al., 2009; Downs et al., 2009; Green et al., 2002; Gute et al,, 2009; Krieger et al., 2009a; Krieger et al., 2009b; May et. al, 2008; Morello-Frosch et al., 2009; Vallianatos et al., 2004].

Targeted health behaviors included in the Partnerships for Communication projects included increasing physical activity and promoting healthy eating habits, reducing use of toxic cosmetic products, and increasing the use of nontoxic “green” cleaning agents by domestic, or household, workers. The projects also influenced community/institutional change, leading to a direct reduction in exposure to hazardous environmental toxins such as decreased use of toxic cleaning compounds in a large commercial cleaning worksite, controls on airborne contaminants in auto body shops, and reductions in the use of toxins by computer manufacturers. In Chicago and Los Angeles, the projects contributed to actions of school boards to reduce student access to unhealthy foods. A manufacturer of blueberry harvesting rakes began marketing rakes that were physically less stressful on workers and an insurance company encouraged farm company clients to use employee training materials developed by the community. The projects also led to policy changes, such as a New York City Council law to reduce diesel exhaust from school bus idling, a Massachusetts State law prohibiting the use of highly flammable solvents by floor finishing companies and a collaboration with a mayor's task force in Houston, Texas to reduce toxic emissions in the petrochemical industry [Baron et al., 2009]. The success of such collaborations by occupational/environmental health practitioners and community-based organizations has since been replicated in other communities, often expanding into broader and more integrated health initiatives.

Finally, the Minority Worker Training Program (MWTP) established by NIEHS in September 1995, funds programs to recruit and train under- and unemployed individuals living near hazardous waste sites or other contaminated properties. The program trains participants in the skills needed to engage in hazardous waste remediation so that they can obtain work in the environmental field [NIEHS, 2009]. The MWTP targets unemployed workers, especially those living in communities disproportionately affected by environmental exposures. It supports the creation of “green jobs”, such as Los Angeles City's green building retrofit program. Community, workforce development and environmental justice groups, labor and university programs provide job skills, access to health and social support services, health and safety training, and programs to improve workers' self-efficacy to contribute to their community. These training programs have served more than 7,800 workers across the country and placed 5,400 workers in jobs in over 30 communities from Boston to Los Angeles [NIEHS, 2009].